/I Tillage Confierenc
S1ofr Sukinibleu Agicultue
June 24-26, 1997
Holiday Inn West Gainesville, Florida
Institute of Food and Agncultural Sciences
in cooperation with
Federal and State Agencies, Industry and Producers
Special Series SS-AGR-60
University of Florida. Institute of Food and Agricultural Sciences
Cooperative Extension Service, Gainesville, FL
Use of trade names or commercial products in this publication is solely for the purpose of providing
specific information. It is not a guarantee or warranty of products named and does not signify
approval of these to the exclusion of others of suitable composition. No recommendations or
endorsements by IFAS, by the University of Florida, or by other institutions or agencies mentioned
in this publication, are implied.
Proceedings of the
20th Annual Southern Conservation
For Sustainable Agriculture
June 24-26, 1997
R.N. Gallaher and R. McSorley
Institute of Food and Agricultural Sciences (IFAS)
University of Florida
Special Series SS-AGR-60, the Cooperative Extension Service, Institute of Food and
Agricultural Sciences, University of Florida, Gainesville, FL.
1997 Southern Conservation Tillage Conference
for Sustainable Agriculture Planning Committee
Dr. Raymond N. Gallaher, Professor of Agronomy, and Program Chairman, Agronomy
Dept., IFAS, University of Florida, Gainesville, FL.
Dr. David Wright, Professor of Agronomy, Agronomy Dept., NFREC, IFAS, University of
Florida, Quincy, FL.
Dr. Robert McSorley, Professor of Entomology and Nematology, Entomology and
Nematology Dept., IFAS, University of Florida, Gainesville, FL.
Mr. Daniel L. Polk, Coordinator of Research and Programs, Agronomy Dept., IFAS,
University of Florida, Gainesville, FL.
Dr. Ben Whitty, Professor of Agronomy, Agronomy Dept., IFAS, University of Florida,
Dr. Carrol G. Chambliss, Associate Professor of Agronomy, Agronomy Dept., IFAS,
University of Florida, Gainesville, FL.
Mr. Winston D. Tooke, Agronomist, UDSA-NRCS, Gainesville, FL.
Mr. Pat Cockrell, Director/Agricultural Policy Division, FI. Farm Bureau, Gainesville, FL.
Dr. Edwin C. French, Associate Professor of Agronomy, Agronomy Dept., IFAS, University
of Florida, Gainesville, FL.
Dr. Ken Quesenberry, Professor of Agronomy, Agronomy Dept., IFAS, University of
Florida, Gainesville, FL.
Editors: R.N. Gallaher R. McSorley
Administrative Advisors: Dr. Jim App, Assistant Dean for Extension, IFAS, UF
Dr. E.R. Emino, Assistant Dean for Research, IFAS, UF
Dr. Joe Joyce, Associate Vice President, IFAS, UF
The "20th Annual Southern Conservation
Tillage Conference for Sustainable Agriculture" is
another milestone in the history of the advancement of
conservation tillage management of crops and the land on
which they grow in the South. The idea of these
conferences was initiated from conversations with Mr.
Tony Rutz, a representative of Chevron Chemical Co. in
the mid-1970s. We decided to see if other no-tillage
leaders in the Southeast would be interested in
participating in such a conference and if we could obtain
commitments from key individuals in each of these states
to host the conferences for the first 7 yr. Dr. Raymond
Gallaher rejected the suggestion that Florida host the first
conference due to the youthfulness of our program. As an
alternative, we decided to attempt to begin the
conferences in Georgia, the most central location and
where we had just completed an experiment station
project entitled "Multiple Cropping and Minimum
Tillage Systems for the Southeast," and where USDA-
ARS had a long history of work in the area. Dr. Joe
Touchton had just replaced Dr. Raymond Gallaher at
Georgia, had a new project underway, and was willing to
coordinate the first meeting. We further agreed to
attempt to rotate the first seven meetings north and south
after the initial Georgia meeting until the first 7 yr were
completed. Agreements were reached with Associate
Dean Shirley Phillips at Kentucky to host the second
meeting. Dr. Gallaher, in Florida, agreed to coordinate
the third; Drs. Doug Worshum, M.G. Wagger and W.M.
Lewis, at North Carolina, provided leadership for the
fourth; and Dr. Jim Palmer provided leadership for the
fifth at South Carolina. The sixth meeting was at the
University of Tennessee under the leadership of Dr.
Elmer L. Ashburn and Dr. Tom C. McCutchen, and
finally, Dr. Joe Touchton, who had changed
professorships from the Univ. of Georgia to Auburn
Univ., again provided leadership for the seventh at
Auburn, AL. This made the first 7-yr commitment
The general agreement was that the conferences
would have a proceedings published and ready to pass
out to those who registered on the first day of each
conference. We wanted to have a wide range of
participants including: university scientists, USDA
scientists, other state and federal agencies, farmers,
industry, etc. We wanted the publication to be in English
units and papers presented and published so that the
information would have immediate usefulness to
everyone. Whenever possible we wanted to include
successful farmers on the program to tell their story of
how they made no-tillage and multiple cropping systems
work on their farm.
As we approached the 7th "Southeastern No-
Tillage Systems Conference," Dean Shirley Phillips at
Kentucky suggested that we open up these conferences to
the entire Southern states and change the name to
"Southern Region No-Tillage Conferences." Dr. Fred
Boswell at Georgia suggested that we petition the
Research Deans from the Southern region and make this
annual conference an official working group under their
advisorship. This petition was accepted and the
University of Georgia became the first to host the
conferences with the new title under the leadership of Dr.
W.L. Hargrove and Dr. Fred Boswell. The conferences
changed the name again in 1988 by replacing 'no-tillage'
with 'conservation tillage,' and Mississippi State
University was the first to host with the new name
"Southern Conservation Tillage Conference," under the
leadership of Dr. Normie Buehring. The conferences
continued to rotate among the Southern states under this
name until 1993 when the words "for Sustainable
Agriculture" were added to the end of the name of the
working group. This name, "Southern Conservation
Tillage Conference for Sustainable Agriculture," has
continued up until the present time.
Much of our success with the advancement of
no-tillage multiple cropping in Florida can be traced to
the first "No-Till Plus" equipment, invented by Mr.
Gerald Harden, a farmer from Banks, AL. Florida
received the first hand-made unit for our research
program in 1976, a gift from the Harden family and
Brown Mfg. Co. This invention made no-tillage a greater
reality for easily compacted soils of the southern Coastal
Plain. Kelly Mfg. Co., Tifton, GA and Cole Mfg. Co. of
NC soon marketed other versions of this planter as well.
In the 1970s and early 1980s, we saw tremendous
adaptation of conservation tillage in Florida as measured
by no-tillage equipment sales. At one time we had 10 no-
tillage planters and drills and six post direct sprayers
scattered across central and north Florida, available for
on-farm use and demonstrations, all donated by industry.
The initial "no-tillage plus" idea soon changed names to
"in-row subsoil no-tillage" and has since changed first to
"row-till" and today many are calling it "strip-till."
Whatever you want to call this type of conservation
tillage, it is still alive.and well in Florida.
Hundreds of manuscripts have been published
in the 19 proceedings by this working group over the past
20 yr. We have had a proceedings every year but one.
The nature of this show and tell working group has made
a highly significant impact on conservation of our natural
resources, not only in the southern U.S.A. but also
literally all around the world. Many of the leaders of
conservation tillage systems in the South have traveled all
over the world giving short and long courses, consulting
in other ways, hosted international visitors at our
workplaces and in our homes, communicated in other
ways, trained national and international graduate students,
etc., and have made a huge impact on conservation of
natural resources for the good of mankind.
Each time a state plays host to this conference,
tremendous effort is expended to involve as many of the
players in conservation tillage as possible. We not only
are expected to have a good proceedings and an extensive
exchange of oral and poster presentations but we are also
expected to provide tours to show and tell what we are
doing. This mode of exchange forces us to do the best
job possible when it is our turn to perform this work.
Industry has been indispensable in making these
conferences a success. They have come through in
providing the necessary extra assistance, without which
the conferences would likely not have happened. We all
owe this group a round of applause. Another group who
also deserve recognition include the administrative
leaders of our Land Grant Institutions. For example, if it
were not for the leadership of Dr. K.R. Tefertiller, former
Vice President of Agriculture and Natural Resources,
Univ. of Florida, many of us involved, here in Florida,
with the present conference would not be here today. His
leadership was the major factor in obtaining legislative
approval for many new positions in IFAS (Institute of
Food and Agricultural Sciences), Univ. of Florida, in the
mid 1970s and 1980s in the areas of conservation tillage,
multiple cropping, water conservation, pest management,
etc. His leadership at national level resulted in the
establishment of CARET (Council of Agricultural
Research, Extension, and Teaching), a nation-wide grass
roots advisory group who provide a unified national voice
to promote agricultural interest. His international
leadership included his promotion and support of IFAS
faculty to be involved at both the national and
international levels to enhance information exchange. He
provided leadership in helping establish the Land Grant
Teaching, Research, and Extension model in many
Other administrators can also be cited, who
have dedicated themselves to the upward movement of
conservation tillage such as Dr. John Woeste, former
Dean of Extension (recognized for his tremendous ability
to network and his leadership in the area of a safe
environmental agriculture), and Dr. Al Wood (deceased),
former Dean for Research who was co-author of the
"Silver Bullet" that was written in cooperation with OMB
and was included into President Reagan's budget that
established Biotechnology as a major national research
effort. We will see the results of some of this technology
on 26 June as a part of the tour, in the form of Roundup
Ready cotton, Roundup Ready soybean, and Liberty Link
corn. Dr. James M. Davidson, present Vice President
for Agriculture and Natural Resources, Univ. of Florida,
among other major accomplishments, provided major
local, regional, and national leadership in the area of
water quality from which we are seeing millions of
dollars being invested today throughout the U.S.A.
(conservation tillage plays a major role in this national
research thrust area). Dr. James (Jim) App, Asst. Dean
of Extension, IFAS, Univ. of Florida, is another unsung
hero who, day in and day out, networks with faculty, other
administrators, and the public to see that the job of
carrying out major extension efforts gets done and
reports are made in a timely and professional way.
Another faithful individual to this conference is Dr. John
I. Sewell, long-time Administrative Advisor to our
working group, he deserves a note of special recognition.
He faithfully participates in our meetings and provides
encouragement, gives us updates on what's happening in
the region, and assists the working group in keeping
focused on our goals.
Many people deserve recognition for providing
support to make this "20th Annual Southern
Conservation Tillage Conference for Sustainable
Agriculture" possible. Key people and organizations are
listed in the program, a copy of which is permanently
attached in the appendix of this proceedings. However,
two organizations deserve special mention, the Florida
Farm Bureau Federation and its leadership (Mr. Pat
Cockrell and Mr. Carl Loop) and the USDA-NRCS and
its leader (Mr. Niles Glasgow) for providing significant
monetary support. Many others made significant
contributions as well and are recognized as mentioned
above. Special appreciation is extended to Dr. Robert
McSorley and Ms. Wanda Gallaher for their long hours
assisting in editing and compiling the proceeding.
We decided the theme for this conference would
be "Partners for a Wholesome Food Supply." Although
not all are represented, we have attempted to involve
many of the partners in this conference. We have an
outstanding slate of participants. You should focus on the
fact that, we, the partners, are interdependent in the
production of a wholesome food supply! Which of the
partners can we do without? I say, none of them!
Otherwise, our progress for production of this wholesome
food supply, while maintaining a wholesome environment
for us to live in, would be greatly diminished. All of the
partners are essential to our ability to meet the goal of a
greater sustainable agriculture, necessary not only for
people today but also for generations to come. Therefore,
we must not only answer to the people in general, but we
must also answer to and effectively network and
communicate with all of the players in the infrastructure
who are involved in the production of a wholesome food
supply. Life and the natural resources on this good earth
deserves no less of us.
Raymond N. Gallaher
TABLE OF CONTENTS
Evolving Communication to Inform and Educate
Ricky W Telg and Larry J. Connor........................................................ ............ 1
Partners in Production of a Wholesome Food Supply
Role of the Institute of Food and Agricultural Sciences in the Production of
a Wholesome Food Supply
Joseph C Joyce .................................................................................................. 8
Role of USDA, Natural Resources Conservation Service (NRCS) in Production of
a Wholesome Food Supply
T. N iles G lasgow ................................................................................................... 12
Role of the Florida Farm Bureau in Production of a Wholesome Food Supply
W m Patrick Cockrell...................................................... ... .................... 14
Role of Soil and Water Conservation of the Office of Agricultural Water Policy
D avid V ogel.................................................................................... ........................... 16
Role of Water Management Districts in the Production of a Wholesome Food Supply
Jerry Scarborough.................................................................................................. 19
Role of Conservation Tillage in Production of a Wholesome Food Supply
Raymond N. Gallaher and Larry Hawf..................................................................... 23
Sustainable Agriculture in Production of a Wholesome Food Supply
E .T Y ork, Jr........................................................................................................ 28
Recycling Urban and Agricultural Organics in Fields and Forests
Wayne H. Smith and Aziz Shiralipour.................35............. 35
Use of Animal Manure in Production of Wholesome Food
H.H. Van Horn, Jr., and P.W Joyce...................................................................... 40
Organic Farming Practices
J.J. Ferguson and M M esh.................................................... ............................. 47
Converting Conservation Reserve Program Contracts to Cropland in Oklahoma
J. H Stiegler, T.H. Dao, and T.F. Pepper................................................................. 52
Telogia Creek Conservation Tillage Project
B.F. Castro, J.C. Love, B.R. Durden, F. Johnson, and H.G. Grant........................... 56
Obstacles to Sod-Seeding Winter Annual Forages in Mississippi
David J. Lang, Robert Elmore, and Billy Johnson..................................................... 60
Alternative Arkansas Rotation and Tillage Practices
C. R. Dillon, T.C. Keisling, B. D. Riggs, and L.R. Oliver........................................... 65
Methods for Managing Nematodes in Sustainable Agriculture
R McSorley and R.N. Gallaher..................... ..................... 75
Cover Crop and Herbicide Burndown Effects on No-Till, Water-Seeded Rice
P .K B ollich......................................................................................................... 80
Mineral Concentration and Content for No-tillage Tobacco Following
Simulated Excessive Rainfall and Supplemental Nitrogen Fertilizer
E. B. W hitty and R.N Gallaher............................................... ........................... 88
Nematode Population Levels on Vegetable Crops Following Two Winter
R. M cSorley and R N Gallaher............................................... .......................... 96
Lupin Hay as an Organic Fertilizer for Production of 'White Acre' Cowpea
Cindy E. Wieland, Jorge A. Widmann, and Raymond N. Gallaher............................ 100
Assessment of Soil Incorporated Crimson Clover Hay as an Organic Fertilizer
Source in the Production of Bush Bean
Brett L. Wade, Stuart J. Rymph, and Raymond N. Gallaher..................................... 108
No-Till Production of Irish Potato on Raised Beds
R onald D M orse......................................... ......... ......................... ...................... 117
Use of New Genotypes of Small Grain and Soybean in Conservation
R.D. Barnett, A.R. Soffes Blount, and D.L. Wright................................................... 122
Value of Roundup Ready Technology in Strip-Tilled Soybean
D.L. Wright, P.J. Wiatrak, B. Kidd, W. Koziara, T. Piechota, J. Pudelko,
and D Z im et........................................................ .............. ................................. 126
Wheat Residue Management in Arkansas Double-Cropped Soybeans
Caleb A. Oriade, Carl R. Dillion and Terry C. Keisling......................................... 133
Cover Crops for Weed Control in Conservation-Tilled Soybean
D.W. Reeves, M.G. Patterson, and B.E. Gamble..................................................... 140
Soybean Yield Response to Tillage and Landscape Position
J.R Johnson, K. C. McGregor, and R.F. Cullum....................................................... 143
Timing of Deep-Tillage for Wheat-Soybean Double Crop in the SE Coastal Plain
W.J. Busscher, P.J. Bauer, and J.R. Frederick...................................... ................... 150
An Economic and Agronomic Evaluation of Selected Wheat Planting Methods
T.C. Keisling, C.R. Dillon, M.D. Oxner, and P.A. Counce....................................... 156
Organic Waste, Conservation Tillage, Soil Quality
Establishing the Value of the Phosphorus and Potassium Contained in Poultry
Litter for a No-Till Corn and Soybean Rotation
J. H G rove.......................................................................................................... 169
Application of Unprocessed Urban Plant Debris Directly to Land.
Gerald Kidder, Marvin F. Weaver, David O'Keefe, and Richard W. Vories................. 175
Use of Dairy Manure Effluent in a Rhizoma (Perennial) Peanut Based
Cropping System for Nutrient Recovery and Water Quality Enhancement
E.C. French, K.R. Woodard, D.A. Graetz, G.M. Prine, and H.H. Van Horn............... 176
Effects of Farm Management on Soil Quality
E.E. Huntley, M .E. Collins, and M .E. Swisher............................................................. 184
Reducing Surface Disturbance with No-Till and Low-Till Systems for Cotton
in the Mid-South
Gordon R. Tupper and Harold R. Hurst................................................................... 189
Nitrogen Management for No-Tillage Cotton
J.J. Varco, J.M Thompson, and S.R. Spurlock........................................................... 195
Influence of Starter Fertilizer on Strip-Till Cotton
P.J. Wiatrak, D.L. Wright, J.A. Pudelko, and B. Kidd.............................................. 199
Strip-Till Versus Conventional Tillage on Yield and Petiole-Sap Nitrate of
Cotton and Soil Nitrate
F.M. Rhoads, D.L. Wright, P.J. Wistrak, and S.T. Reed........................................... 204
Cover Crops and Tillage Practices for Cotton Production on Alluvial
Soils in Northeast Louisiana
E.M., Holman, A.B. Coco, and R.L. Hutchinson................................................... 208
Cover Crops for Weed Control in Conservation-Tilled Cotton
M.G. Patterson, D.W. Reeves, and B.E. Gamble................................ .................. 211
Tillage and Cover Crops Affect Cotton Growth and Yield and Soil
D.J. Boquet, R.L. Hutchinson, W.J. Thomas, and R.E.A. Brown................................ 214
Winter Crop Effect on Double-Cropped Cotton Grown With and
Phillip J. Bauer and James R. Frederick.................................................... ............... 220
Management of Reniform Nematodes in Strip Till Cotton Treated with
Temik 15G and Telone II, Including Use of Telone II at Planting
J.R Rich, S.K. Barber, R.A. Kinloch, and D.L. Wright............................................ 223
No-till Cotton: Redvine Control on Clay Soil
H arold R H urst.................................................................................. ...................... 227
Weed Management in No-till Roundup Tolerant Soybean and Cotton
B arry J. B recke..................................................................................................... 233
Corn Forage Yield and Cost of Silage Production from Use of Yard
Waste as Compost
P.E. Hildebrand, RN. Gallaher, and R. McSorley....................................................... 238
Weed Control for Corn Planted into Sod
M .L. Broom e, and G .B Triplett................................................................................. 245
Influence of Conservation Tillage Practices on Grain Yield and Nitrogen
Status of Corn Grown on an Alluvial Clay in Louisiana
H.J. Mascagni, Jr., R.L. Hutchinson, B.R. Leonard, and D.R. Bums......................... 250
Tillage and Soil Insecticide Effects on Dryland Corn Yields
J.E. Matocha, S.G. Vacek, and F.L. Hopper.................................... ..................... 255
Research Techniques Using Precision Agriculture Technology
Roberto Barbosa, John Wilkinson, William Hart, Paul Denton,
Roland Roberts, Don Tyler, and Don Howard.......................................................... 266
Effect of Low Input Technology on Tropical Corn Production on
C.S. Gardner, C.H. McGowan, R.L. Carter, C.L. Brasher, and G.L. Queeley.................. 270
Corn Performance Trails in Quincy and Gainesville, Florida
R.L. Stanley and R .N G allaher................................................................................... 281
Past Conferences, Coordinators, and Proceedings.................................... .................... 288
Editorial C om m ents........................................................................................................ 292
1997 Southern Conservation Tillage Conference Regional Steering Committee.............. 294
A cknowledgm ent and Sponsors........................................................................................... 297
Program of 20th Annual Southern Conservation Tillage Conference for
Sustainable A agriculture ...................................................................................................... 298
Evolving Communication to Inform and Educate
Ricky W. Telg and *Larry J. Connor
With the incorporation of new and evolving
communication technologies, such as satellites,
compressed video, and computers, education has taken on
a new "flavor" in recent years. In the classroom,
computer presentation software and multimedia computer
workstations are becoming the chalkboards and overhead
projectors of a new generation. More schools are getting
"wired" to the Internet (Slater, 1996), universities are
placing entire degree programs on the World Wide Web
(Thorson, 1989), and corporations are investing millions
into professional development using computers and
television (Arnall, 1987; Bruce et al., 1991; Galagan,
1989; Portway, 1993).
With this emphasis on communication
technologies as a means of teaching students, professional
educators and corporate businesspeople will have to learn
how to learn by and teach with these evolving
communication technologies, both in the classroom and
at a distance. This paper examines some of these
communication technologies and their use in information
dissemination, some major educational concerns related
to them, options for using communication technologies in
the classroom, implications for professionals, and major
Many people have expressed concerns about
teaching with new communication technologies. "Why
change?" they ask. "We've been doing fine for years
teaching our courses the way we've always taught our
courses." That may have been true for the past and for the
present, but the future may very well belong to those who
incorporate communication technology-mediated
education. In classrooms, technology can aid in students'
retention of information. Studies have shown students at
a distance do as well or better than their student
counterparts in traditional classrooms (Chu and
Schramm, 1975; Whittington, 1987). Using new
technologies means communication no longer has to
occur in "real time" (synchronous). The asynchronous
'R. W. Telg and 2L. J. Connor. 'Agr. Educ. and Comm.
Dept., and 2Dean of Academic Programs, College of
Agriculture, Univ.ofFlorida, Gainesville, FL. Manuscript
received 3 March 1997. Corresponding author.
("non-real-time") communication that technology-
mediated instruction allows means information can be
moved to the people who need it, at their time, at their
Communication technologies have advantages
beyond their demonstrated educational effectiveness. In
the case of teaching to students at a distance, instructors
do not have to invest large amounts of travel time going
to and from a distant location. Travel costs also are cut
considerably. As a result of the up-front time that goes
into planning a distance education program, instructors
have noted that their teaching materials (videotapes,
computer programs/applications, detailed printed hand-
outs, computer graphics) are better than those they would
design for a regular "face-to-face" classroom.
Teaching with communication technologies
does have drawbacks, though. Interaction tends to be
stilted; communication seems impersonal because it is
not "really" face to face. Start-up costs tend to be
expensive. And faculty do have to invest a great deal of
up-front time to develop their classes.
Communication Technologies in the Classroom
The face of classrooms is changing. Multiple
media -- or multimedia -- is the "buzz word" in education
today. Computers with video, audio, and text capabilities,
linked to CD-ROMs, videodisk players and the Internet,
have taken "multimedia" to a new level. Students now
can reach beyond the constraints of their classroom's four
walls. For example, many universities are placing
classroom material on-line for students on-campus, not
just for those at a distance. On-line manuals and
textbooks in hypertext and hypermedia formats are
becoming commonplace. Lectures can be live
(synchronous) or on demand (asynchronous) through
World Wide Web pages in a hypertext format (Kouki and
Wright, 1996; Oakley, 1997). Libraries are placing
relevant material directly on the World Wide Web.
Listservs (electronic mailing groups) are used in an ever-
growing number of classes so students can discuss
subjects of global interest to other students in their class.
Instructors use "virtual" office hours through e-mail to
stay in contact with students throughout the day or night.
Following are some other examples of new classroom
technologies and their uses.
Computer side/graphic programs (PowerPoint,
Harvard Graphics, Persuasion). More instructors are
using computer graphics programs, instead of
transparencies, to display their classroom notes, video,
graphics, and photographs with a small laptop computer,
coupled with a high-intensity overhead projector. If the
room has a network connection, material from the Web
also can be shown. Once the notes are input in the
computer, instructors can easily revamp them for future
classes, place them on the Web, or print out notes for
Multi-user dimension (MUD) environments. This
new Internet tool is for real-time, text-based, multi-party
communication. These computer programs offer their
users text-based shared virtual environments that they can
explore using simple commands. Users meet, have
brainstorming sessions, and exchange information via
Multimedia computers in the classroom. Multimedia
computers with CD-ROMs, installed in classrooms and
networked to the Internet, allow instructors to bring a
new dimension to the learning environment. Students can
read text, see graphics and video, and hear audio.
Communication Technologies at a Distance
In this section, the major technologies available
for distance education and their advantages and
disadvantages (Smaldino, 1995) will be briefly outlined.
"Low-tech" methods (Table 1) can be characterized by
limited or no interactivity between instructor and student.
"High-tech" methods (Table 2) allow more interactivity
through more advanced technology.
Implications for Professionals
This section describes some of the implications
professionals will have to consider as they develop
programs to be taught with communication technologies.
Although this section focuses more on a distance
education model, many of the methods apply when
incorporating technology in the classroom.
Teamwork. Providing instruction to students at a
distance is not the responsibility of the instructor alone.
In the distance education framework, teamwork,
comprised of instructional designers, television-
production specialists, computer specialists and other
technical support personnel, becomes important in the
development and dissemination of instructional materials
(Brinkley et al., 1991; Collins and Murphy, 1987; Kelly,
Instructors or subject matter specialists are
experts in their areas of content. Subject-matter
specialists should not become technology experts; rather,
they should be able "to understand the basics of the
technology and how communication is being mediated"
(Thach, 1993, p.295). The distance education
instructional designer must function in relationship to the
infrastructure as a reference for the resources available in
that academic institution, must know how certain
technologies and media work, and must serve as an
intermediary and mediator between the instructor and
technical specialists (Brinkley et al., 1991). Educational
technologists, such as computer specialists and
educational television producers, have the production
expertise to assist in the development of the program or
course. Because of their professional backgrounds, they
understand the specific instructional design needs
dictated by the requirements of the media (Smith, 1991)
and how to better provide instruction through this form of
mediated communication (Garrison, 1989; Hart, 1984).
Support staff ensure that all of the little details
are taken care of so a distance education program can run
smoothly and successfully by handling such tasks as
student registration, materials duplication and
distribution, and facilities scheduling. Site facilitators
should be able to handle technical problems that may
arise at the sites and be well-versed in interactive
strategies to involve the students as much as possible in
the course activities.
Instructional Design. Instructional design is important
in any educational setting and is defined by Gaff (1975)
as the systematic and continuous application of learning
principles and educational technology to develop the
most effective and efficient learning experience for
students. Several instructional design models exist for
teaching with technology (Kemp, 1985; Murphy and
Taylor, 1993; Price, 1994). In any instructional design
model, the following questions must be asked. The
instructional design elements then will be discussed.
What is the need for the distance education program?
What are the goals and objectives?
Who will be the learners?
What will be the subject content (message)?
What teaching methods and media will be used?
How will learners be assessed?
How will the course or lesson be evaluated with
a view to improvement?
A needs assessment, to determine why the
instruction is required, should take place before the rest
of the design process is undertaken. Goals and objectives
structure the instructional plan of action. A goal is a
general statement of what you hope the course (or
program) will achieve, perhaps expressed in terms of
what you, the teacher, will be presenting to the learner.
An objective is a statement of what learners should be
able to do (or do better) as a result of having worked
through the course (or program).
In any instructional environment, it is imperative
to know as much about the learner -- the intended
audience -- as possible. The audience for each course
most likely will be somewhat different. However, there
are some common characteristics regarding the "distance
learner." Distance learners tend to be older, have
established jobs and families, are self-motivated, expect
limited interaction with their instructors, and are usually
excited about taking a much-needed distance education
The message should be decided even before a
medium is chosen. What are you trying to say? Is it
appropriate for communication technologies? How is the
best way to integrate the message with the technology?
The technology should be selected to meet the needs of
your class. The medium/media choice should come after
you decide what you want to say. In your courses, you
want to provide media variety to your students; integrate
voice, video, and data technology with print resources.
Assessment and evaluation should be
components of any instructional endeavor. Assessment
can take the form of a needs assessment to determine why
the course is necessary and student assessments (tests and
assignments). Evaluation should be part of the course
throughout the span of its existence -- through formative
evaluations given during a semester and a summative
evaluation given at a course's completion. The purpose
of the evaluation should be improvement of the course.
Revisions should be done as a direct result of the
evaluation process and feedback from colleagues and
content specialists. Because assessment and evaluation is
so important, yet often overlooked, in the design of a
technology-mediated program, a closer look at
assessment and evaluation components is provided here.
Teaching Strategies. For the most part, effective
distance teaching requires enhancing existing skills,
rather than developing new abilities. For example,
educators will have to "chunk" their instruction more, by
spending no more than 10 to 15 minutes lecturing without
some type of "break." The "break" allows students to
process what they have just been exposed to. Also,
educators must prepare for the course in advance and not
wait until the day before (or morning of) a class to get
ready. This helps to allow for time to built in for course
materials sent in the mail to get to their intended
Interaction. Distance education requires different
communication methods than those needed in traditional
classrooms (Zvacek, 1991) because information
technologies are predominantly visual, as opposed to the
textual and auditory environment of the conventional
classroom (Dede, 1991). Designing systems of feedback
is of concern in mediated communication (Garrison,
1989). However, interaction does not have to occur in
"real time" to be effective. "Virtual interactivity,"
occurring through asynchronous means, such as
computers (e-mail), facsimile, and surface mail, is
effective in bridging the communication gap between
instructors and off-campus students who view videotape
programs in their homes (Russell, 1994).
Perhaps the biggest headache for faculty
members in the distance education environment is the
lack of nonverbal cues. Not being able to gauge how well
one is teaching has been seen as a disadvantage of a
distance education system. The educator must have
confidence in yourself that the content is what should be
taught The feedback from the formative evaluations, the
telephone calls and electronic mail messages will help
gauge the teaching's effectiveness. The key, then, to
interactivity is thoughtful instructional design that takes
into account teaching objectives, creative teaching
methods, and appropriate distance delivery technologies
(Murphy, 1992). For example, educators should call on
sites, because rarely will someone break in with a
question. And when an educator asks a question to a site,
the educator should employ the "10-second rule" -- wait
at least 10 seconds before saying anything else or going
to another site. This allows students some time to think
about a response.
Probably the area that is thought about the least
in a distance education production is marketing. But
without some marketing plan, a distance education
program is doomed from the point of view of low
enrollment. The consideration of marketing a program
should come on the very heels of the idea for the program
itself. When identifying the audience, thought should be
given about how to let the target audience know about the
distance education production. With no audience, there is
After a target audience is identified, the next
step is to advertise. People need to know how the course
would benefit them. Some places or ways that
agriculture-related programs may advertise are the
following: word of mouth and direct contact, commodity
magazines and newspapers, other organizations that are
partners in the distance education program, paid
advertisements on radio and television stations,
newsletters and fliers, and county Extension agents.
EMERGING POLICY ISSUES
Evolving communications technology and
information delivery systems have precipitated some
emerging policy issues. To date, major policy issues
appear to be the determination of user needs, the
financing of technological infrastructures, the resolution
of communications, property rights, and the professional
development of instructors. In some cases, market forces
will have a major impact upon the resolution of these
policy issues. However, other issues will necessitate
public policy resolution at governmental or legal levels.
Major examples of emerging policies issues are included
in this section.
Which users will receive the primary attention,
and which of their needs will be addressed? In the
agricultural sector, evolving communications technology
can be used to work with the infrastructure serving
farmers (agribusiness, extension agents, federal agency
personnel, and others). Alternatively, evolving
communication technology may be used directly with
production and marketing firms.
User needs may be met in a variety of ways:
formal degree programs, college credit courses, short
courses, and seminars, to name a few. If profits can be
realized from providing these types of information,
competition can be expected in the private sector as well
as from competing universities and other public sector
institutions. Determining user needs has always been a
difficult process, as many Extension and Soil
Conservation Service personnel can testify.
Financing Technological Infrastructures
Start-up and maintenance costs may be
significant in the provision of distance education
technology, and in the enhancement of classroom settings
with modem multimedia equipment. Satellite delivery
systems include uplink and downlink equipment,
transponder costs, faculty development costs, and
materials. Two-way audio-visual systems also may have
considerable start-up and maintenance costs.
The manner in which these costs are financed
will influence the adoption rates of evolving
communications technology. User fees, tuition charges,
and other assessments may cover part of the costs.
However, most public institutions will require some "up-
front" funds to initiate their programs. To date, the
response is very different between states. States such as
Iowa, Georgia, and Maine have made major financial
commitments to distance education. Many other states
have done little.
Classroom instructors have long been sensitive
to the reproduction of notes and classroom materials for
sale. Computer users have become increasingly sensitive
about property rights in the utilization of computer-based
materials. Communications property rights can be
expected to become increasingly more complex with the
advent of new technology.
As an example of the complexity, consider inter-
university cooperation in the provision of courses. At
some universities, it is extremely difficulty to transfer
credits from other universities. Some universities cannot
offer distance education courses unless students are fully
matriculated. Some colleges do not wish to relinquish the
provision of some of their courses to competing state
universities for fear of losing state financial support.
The advent of modem communication
technology and information delivery systems has resulted
in a major need to retrain generations of instructors. The
ability to use modem educational technologies is
probably at least as demanding as the ability to use
modem laboratory research equipment. Many faculty
historically only used overhead projectors, blackboards,
and slide projectors. Moving to higher-level
technologies will require major human capital
investments. Determining who supplies this training, and
how it is financed will be major factors in the evolving
The resolution of the above emerging policy
issues will require major private sector initiatives and
public sector investments. The current conservative
political environment and interest in "budget cutting" will
unquestionably influence public expenditures for
communications technologies and information delivery
Educators will have to stay abreast of
communication technologies in order to inform and teach
effectively in the future. Not only that, but communication
technologies also will affect how educators receive
information. For example, many academic journals
already seek manuscript submissions in an electronic
format, and produce on-line editions of the journals.
Universities and corporations are promoting research and
products on the Web. Communication via e-mail with
colleagues across campus, the state, country, and world,
many times, is easier and less expensive than
"conventional" communication with telephone or the
Postal Service. Many professors are using Web sites,
instead of formal textbooks, with which to teach courses.
Communication technologies for classroom and
distance instruction will continue to evolve, expand, and
improve. As has been shown in this paper, evolving
communication technologies are causing educational
methodologies to change, as well. Educators, themselves,
will have to become life-long learners so their teaching
methods will evolve as the technology evolves. But
educators will not have to do it alone. They can make the
transition with assistance from educational technology
experts and instructional designers and through the
suggestions presented in this paper.
Arnall, G. 1987. Satellite-delivered learning. Training
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Brinkley, R., G. Pavlechko, and N. Thompson. 1991.
Designing and producing courseware for
distance learning instruction in higher
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Bruce, C., E. Katz, and J. Tomsic. 1991. Industry
training and education at a distance: The IBM
approach. Annals Amer. Acad. 514:119-132.
Collins, V., and P. Murphy. 1987.. A new adult student:
Learning by interactive satellite. Continuing
Higher Educ. Rev. 51(2):29-37.
Chu, G., and W. Schramm. 1975. Learning from
television: What the research says. ERIC
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Dede, C. 1991. Emerging technologies: Impacts on
distance learning. Annals Amer. Acad. Polit.
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Gaff, J.G. 1975. New approaches to improve teaching.
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Galagan, P. 1989. IBM gets its arms around education.
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Garrison, D. 1989. Understanding Distance Education:
A Framework for the Future. Rutledge, NY.
Hart, I. 1984. Video and the control of knowledge. pp.
84-92. In O. Zuber-Skerritt (ed.), Video in
Higher Education.. Kogan Page, London.
Kelly, M. 1990. Course creation issues in distance
education. pp. 77-100. In D. Garrison and D.
Shale (eds.),. Education at a Distance.
Krieger, Malabar, FL
Kemp, J.E. 1985. The Instructional Design Process.
Harper & Row, New York, NY.
Kouki, R., and D. Wright. 1996, July. Internet distance
education applications: Classification and
case examples. Education at a Distance
Murphy, D., and G. Taylor. 1993. A tale from the mud.
pp. 55-76. In M.S. Parer (ed.), Developing
Open Courses. Centre for Distance Learning,
Churchill, Victoria, Australia.
Murphy, K. 1992. How to create environments for
active rather than passive learning. pp. 131-
136. In Proc. JTCA Teleconf. Yearbook
1992. International Teleconferencing
Association, Washington, DC.
Oakley, B. 1997. Asynchronous learning. Presentation
to Institute of Food and Agricultural Science
faculty. Gainesville, FL. -
Portway, P. 1993. How corporate America trains by
telecommunications. Communications News
Price, R.V. 1994. Price/Repman model for instructional
design for college-level courses using
interactive television, pp. 191-198. In Distance
Learning Research Conference, San Antonio,
Russell, T. 1994. Is interactivity essential? Overrated?
Detrimental? Paper presented at Educom 94,
San Antonio, TX.
Slater, E. 1996. Online classes launch CSUN into
cyberspace. Los Angeles Times. (December
Smaldino, S. 1995. Technology. Paper presented
during A Model Program for Staff and Faculty
Training in Agricultural Distance Learning
seminar, Ames, IA.
Smith, D. 1991. Video Communication: Structuring
Content for Maximum Program Effectiveness.
Wadsworth, Belmont, CA.
Thach, L. 1993. Exploring the role of the deliverer in
distance education. Internat. J. Instruct. Media
Thorson, M.K. 1989. Campus-Free College Degrees,
4th Ed.Thorson Guides, Tulsa, OK.
Whittington, N. 1987. Is instructional television
educationally effective? A research review.
The Amer. J. Distance Educ. 1(1):47-55.
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distance education. Tech Trends 36(1):40-43.
Table 1. "Low-tech" methods.
Student can work at own pace
Support materials (print)
Students can review audio tapes
Use of motion and audio
Student can work at own pace
Students can review videotapes
Low completion rate
Difficulty in communicating between
teacher and student
Same as audio cassettes
Lecture-style presentation (although can be
supplemented with video segments)
Radio Audio -- listen to teacher
Review materials (print)
Similar to on-site lectures
Same as audio cassettes
Student can't work at own pace
Same as video cassettes
Motion and audio
Review materials (print)
Similar to on-site lectures
Access to computer
Difficulty in communicating between
teacher and student
Same as audio cassettes
Student can't work at own pace (shown at
specific times) unless videotaped
Lecture-style presentation (although can be
supplemented with video segments)
Table 2. "High-tech" methods.
(Use of telephones
to bring many people
together in an
Many courses offered this way
Students can read teacher's
Work at own pace
Review computer materials
Live dialogue with e-mail
Access to telephone
Listen to teacher's presentation
Student can work at own pace
Live dialogue with teacher and
Motion and audio
Can see and hear teacher's
Student can review (if taped)
Students can speak to teacher
Students can see and hear teacher
and be seen and heard
Access to a computer
Time-delay for written materials
Time-delay for written materials
Access to facilities
Students can't work at own pace
(shown at specific times) unless videotaped
Time-delay for written materials
Costs of greater bandwidth
Access to classroom (or computer)
Poor video quality
Time-delay for written materials
Role of the Institute of Food and Agricultural Sciences
in the Production of a Wholesome Food Supply
Joseph C. Joyce
To understand the role of the University of
Florida's Institute of Food and Agricultural Sciences
(UF/IFAS) in the production of a wholesome food supply,
one need only look at the organization's mission and
vision statements which were developed as a part of a
strategic planning process known as Florida 2000 and
Beyond (Anon., 1995).
"To develop knowledge in agricultural, human,
and natural resources, and to make that knowledge
accessible to sustain and enhance the quality of human
"The vision for UF/IFAS is to increase and
strengthen the knowledge base and technology
EXPANDING the profitability of global
competitiveness and sustainability of the food,
fiber, and agricultural industries of Florida.
PROTECTING and SUSTAINING natural
resource and environmental systems.
ENHANCING the development of human
IMPROVING the quality of human life."
In order to implement the mission and vision in
response to Florida's rapid socio-economic, technological
and environmental changes, UF/IFAS has established
nine initiatives. These initiatives represent specific
interdisciplinary program areas and are included in the
UF/IFAS annual budget request as critical issues to be
funded as partnership programs with other agencies or
private entities. These initiatives are:
Environmentally Compatible Pest Control
As new exotic pest, environmental restrictions,
and the loss of traditional control methods increase,
agriculture and urban pest management will become
more difficult threatening the $6.0 billion agricultural
J. C. Joyce, Associate Vice President for Agriculture and
Natural Resources, University of Florida, Institute of
Food and Agricultural Sciences, Gainesville, FL.
Manuscript received 3 April 1997.
industry and urban environments. Integrated Pest
Management (IPM) programs will target crop protection,
urban pest management, and the protection of natural
Food Safety and Quality
Research and education programs will identify
critical issues affecting the safe production, processing,
and marketing of seafood and other meats, and
vegetables. These programs will protect and enhance the
economic viability of Florida food industries and provide
for increased consumer safety and satisfaction.
Sustainable Water Resources
In order to protect the state's water resources
from agriculture operations and urban development, Best
Management Practices (BMPs) will be developed for
water quality protection, water conservation, urban and
rural nutrient and pesticide management, exotic pest
management, soil subsidence reduction, and wetland
Sustainable Food and Agricultural
Increasing food and fiber needs must be met
with our current resource base. UF/IFAS programs will
improve production efficiencies of farms, ranches, forest,
nurseries, and groves while maintaining environmental
compatibility. These efforts will require multi-
disciplinary efforts among production agriculture,
businesses, and human and natural resources.
Animal Health and Environmental Toxicology
The public demand for a safe and wholesome
food supply has never been greater. However, microbial
agents like E. coli and Salmonella have been found in
food of animal and plant origin and caused numerous
human and food borne illnesses. Hazard analysis and
critical control point (HACCP) programs are being
developed to provide on farm and ranch training to make
certain that food is disease and residue free when
Youth and Family Development
Research and education programs will focus on
parenting, resource management and nutrition, in an
effort to reduce the number of low birth weight infants,
improve nutrition and health and to reduce juvenile
crime, school drop out rates and violent crime rates
Developing Sustainable Rural Communities
Rural communities need assistance to develop
alternative, sustainable sources of economic activity in
order to prevent further decline in rural economies. The
program will concentrate on economic development
through alternative enterprises, community development,
and the development of community leadership.
Expanded Quality Educational Experiences
UF/IFAS will expand the opportunity for all
Floridians to receive a high quality educational
experience both on the central Gainesville campus and at
other UF locations throughout the state. UF/IFAS is
concentrating on increased availability of formal and
informal programs through distance learning
technologies, increased traditional classroom situations
throughout the state, expanded multi-cultural
experiences, interdisciplinary curricula, and improved
recruiting and instruction.
Agricultural and Natural Resource Policy
Decisions and rules regarding land use rights,
water allocation, and natural resource allocation among
competing interests are rapidly evolving. These decisions
affect all citizens including the food, agriculture and
natural resource based industries; rural, urban, and
coastal homeowners; developers and the tourist industry.
However, little attention has been given to what the costs
actually are nor to the resulting socio-economic effect.
Research and education programs will inform policy
makers on the economic impacts of agriculture and
natural resource policies and regulations.
Because these initiatives integrate the functions
of research, teaching, and extension so effectively, their
existence reflects the strongest traditions of the Morrill
Act of 1862 which established the Land Grant University
system and later the Agricultural Experiment Stations
through the Hatch Act of 1887 and the last of the triad,
the Cooperative Extension Service, established in 1914
by the Smith-Lever Act. The UF/IFAS system has
expanded through the establishment of a diverse and
wide-spread system with faculty located at the main
campus in Gainesville, at Research and Education
Centers (RECs) throughout the state and county
extension offices in each of Florida's 67 counties (Figure
1). Under this arrangement approximately 40 % of the
faculty are located at the statewide RECs, but are tenured
within their disciplinary department on the Gainesville
The unique organizational feature of UF/IFAS
is the close integration within a single organization of the
functions of research, extension, and teaching to meet the
needs of the state in agriculture, human, and natural
resources. This organizational structure was envisioned
by Dr. E.T. York in 1964 with the establishment of
UF/IFAS. As Figure 2 indicates, UF/IFAS has 645.5
FTEs of faculty effort; however, by spreading this effort
through split assignments UF/IFAS is able to have 340
faculty involved in teaching activities, 565 in research,
and 242 in extension. There are also an additional 245
county extension faculty. Thus, one can easily see that
the value and unique role of UF/IFAS is the
complementary faculty effort, thus maximizing efficiency,
as opposed to competitive activities, among the functions
of research, extension, and teaching. Faculty, students,
and statewide clientele benefit from the integration of
these functions within an individual faculty appointment.
For example, research efforts provide up-to-date
information to solve customer driven problems through
the extension program. Likewise, the research effort
receives the benefit of feedback from the extension
program on the nature of emerging problems upon which
to focus new research efforts. The teaching program
benefits from a diverse pool of human capital that
possesses the latest research information.
Undergraduate students benefit from direct contact with
faculty expertise and a greater efficiency of delivery.
Graduate students benefit from faculty-directed hands-on
research training and from financing derived from
sponsored research efforts.
As the state's Land Grant University, the
University of Florida and UF/IFAS represent an ongoing
investment in Florida's agriculture, human and natural
resources. Programs are conducted statewide within the
context of a vision for expanding the profitability, global
competiveness, and sustainability of Florida agriculture,
protecting and sustaining natural resource and
environmental systems in Florida, and enhancing the
development ofFlorida's human resources (Koukas etal.,
1997). This unique capability allows UF/IFAS to
provide a service in partnership with Florida's sister
agencies, as well as Federal and private entities.
Anonymous, 1995. Institute of Food and Agricultural
Sciences. Univ. of Florida, Gainesville, FL.
Koukas, P., D. Mulkey, and H. Cothran. 1997.
University of Florida Institute of Food and
Agricultural Sciences: An Investment in
Florida's Agricultural, Human, and Natural
Resources. University of Florida. Gainesville,
IFAS Statewide Research
and Education Network -
O Main Campus *
SResearch and Education Lauderdale
AResearch Sites 0 homestead
SAdministered by RECs
FIGURE I KeyW d
Figure 1. The UF/IFAS faculty located at the main campus in Gainesville, at Research and Education Centers (RECs) throughout
the state, and county extension offices in each of Florida's 67 counties.
1995-96 UF/IFAS Faculty Effort Distribution
* Excludes 248 FTE county faculty.
Figure 2. Numbers and distribution of UF/IFAS faculty among teaching, research, and extension assignments for 1995-1996.
Role of USDA, Natural Resources Conservation Service (NRCS) in Production of
a Wholesome Food Supply
T. Niles Glasgow
United States Department of Agriculture,
Natural Resources Conservation Service (USDA,
NRCS) provides conservation planning and technical
assistance to clients (individuals, groups, and units of
government). These clients develop and implement
plans to protect, conserve, and enhance natural
resources (soil, water, air, plants, and animals) and to
address their social and economic interest (SWAPA +
Planning involves more than considering
individual resources. It focuses on the natural systems
and ecological processes that sustain the resources.
The planner strives to balance natural resource issues
with social and economic needs through the
development of conservation management systems
(CMS) often referred to as conservation plans.
To achieve the goal of sustained wholesome
food supply, many partners work together to provide
the decision maker (client) with viable alternatives.
These alternatives provide different ways to meet the
client's objective and meet the quality criteria of the
resource concerns. Each alternative is evaluated to
determine its effect and impact on the natural resources.
The development of alternatives and the
implementation of a conservation plan is the
culmination of many cooperative efforts. State and
federal agencies such as Colleges and Universities;
Research from Institutes of Food and Agriculture
Science; USDA, Agriculture Research Service;
Cooperative Extension Service; private individuals,
commodity groups and agriculture cooperatives have
all played a major role in developing and transferring
present day knowledge and technology to the decision
The end product is a conservation plan that
combines management and conservation practices that,
when installed, will achieve a specified level of
treatment for all resources. Plans contain soil maps
with interpretations; worksheets and jobsheets such
as forage inventories, erosion estimates and cost
estimates; operation and maintenance agreements and
T. N. Glasgow, State Conservationist, USDA, Natural
Resources Conservation Service, Gainesville, FL.
Manuscript received 26 Feb. 1997.
procedures; a plan map showing land use, fields, acres,
and locations of various practices to be applied; a
record of the client's decisions; other useful maps,
sketches, and designs; and a Conservation Effects for
Decision making worksheet reflecting site-specific
The planned conservation system is evaluated
as to the effect it will have on the resource concerns
(SWAPA + H). The following considerations and/or
problems are evaluated:
Erosion Sheet and rill, wind, and irrigation induced
concentrated flow (ephemeral, classic gully,
streambank; soil mass movement; roadbed
and construction sites)
Condition tilth, compaction, soil contaminants
Quantity Seeps, flooding, subsurface water, restricted
Restricted capacity, water bodies
Water management irrigated
Water management- nonirrigated
Aquatic habitat suitability
Quality Sediment, smoke; chemical drift,odors;
fungi, molds, pollen
Condition Temperature, air movement, humidity
Suitability Adapted to site, intended use
Condition Productivity, health and vigor
Management Establishment, growth, harvest, and
(Domestic and wildlife)
Habitat Food, Cover/shelter, water
Management- Population/resource, balance, animal
A simplified example of a partial alternative
considering the resources is provided below:
Farmer X has 100 acres of row crop and 200
acres of grazing land. Water for the livestock
is supplied in two 100 acre pastures. The
planner follows a three phase, nine step
process. In the process an inventory and
analysis shows soil loss from sheet and rill
erosion rates of 15 tons/a (3 times that
to maintain the soil resource base), a near by
steam laden with sediment and fish kills
occurring 2-3 times a year; production of the
row crop is about state average, input of
fertilizer is high, there is a large lake down
stream from the farm and it is experiencing
eutrophic conditions and has periodic
undesirable algae bloom, the grazing area has
several shallow gullies throughout the two
pastures, the pasture grasses have some areas
that are very short and over grazed while other
areas have mature grasses that are not grazed,
game birds and deer are seldom seen on the
One alternative Farmer X may consider is to apply the
following conservation practices as a part of an overall
Residue Management, Strip Till
Effect: Reduces soil loss to the level so that it
will maintain productivity; water quality improvement
by reducing the amount of sediment carrying attached
nutrients, reducing the amount of sediment in the
stream, and reduce one possible cause of eutropication
of the off site lake; increased crop production build
organic matter in the soil thus improving nutrient and
water holding capacity, reduced cost from most inputs;
increased management level.
Decreased cost and increased production by
applying only the amounts needed, in the appropriate
form, and in a timely manner, reduced eutropication of
lake by reducing the amount of dissolved nutrients
going to the lake.
Increase net profit by scouting and applying
appropriate pest control measures (biological,
chemical, and/or mechanical). Improve water quality
and wildlife habitat by using pesticides with less
potential for leaching and/or runoff and considering the
aquatic index; reduce chemical health hazards to
human, plants and animals; promote beneficial insects.
Prescribed Grazing (Includes Support Practices
such as Fencing, Watering Trough, and Pipeline)
Develop a more desirable plant community,
better utilization of forage, increase production of
forage, produce more animal units (domestic and
wildlife), reduce erosion, improve water quality.
There are many alternatives that could be
chosen and each would have different effects on the
resources. Our natural resources are so closely related
and interdependent. The example above only
demonstrates a partial alternative with some of the
possible effects described.
When one or more resource is manipulated,
the impacts on the others must be considered. The
production of a plentiful, wholesome, sustained food
supply must have the support of the many partners and
we must provide the best available assistance to the
land use decision maker.
Role of the Florida Farm Bureau in Production of a Wholesome Food Supply
Wm. Patrick Cockrell
The objectives of my presentation are to: 1)
present information on the Florida Farm Bureau's role at
the state and national levels in maintaining farm
profitability, sustainability and resource protection, 2)
give examples of the policy impacts of the Food Quality
Protection Act, the Florida Nitrate Law, and the Farm
Bill, 3) explain Florida Farm Bureau's role in those
public policy debates and grass roots farm initiatives, 4)
give an international perspective of the public debate, and
5) discuss the effects of chemophobia as it relates to the
European Community and the possible correlation in the
Subjects to be Covered
EQUIP & Other Programs
Chemophobia vs. Sustainability
FACTS ABOUT FLORIDA FARM BUREAU
Oldest Farm Organization
Florida Farm Bureau is Florida's oldest and
largest general farm organization. It was organized in
November 1941 and today has a membership in excess
of 110,000 member families. A general farm
organization, in this sense, means one which represents
all major agricultural commodities i.e.; citrus, forestry,
row crops, beef, dairy, etc.
Farm Bureau is an independent,
nongovernmental voluntary organization of families who
are united for the purpose of analyzing and solving
common problems. It is local, state, national, and
W.P. Cockrell, Director/Agricultural Policy Division,
Florida Farm Bureau Federation, Gainesville, FL.
Manuscript received 21 March 1997.
international in scope and influence. One of its major
purposes and thrust is legislative involvement and
influence on behalf of the agricultural industry.
Florida Farm Bureau is a "grass-roots"
organization, one which gets its direction and policy from
bona fide farmer-rancher members who adopt policy each
year at the state's annual meeting. The real strength of
Florida Farm Bureau lies in the counties...where the
members live. It's here that the basic needs, thinking and
interests are generated and ideas for service programs are
begun. Being a federation, a state organization can be no
stronger or effective than the sum total of its county
Sixty-Two County Farm Bureaus Make up Florida
There are 62 organized county Farm Bureau
units in Florida. Each county Farm Bureau has a county
president, vice-president, secretary, treasurer, and board
of directors. A person must be actively engaged in
production agriculture to be eligible to serve on a county
Farm Bureau board of directors.
Farm Bureau is 'a service-to-member
organization. Only members may participate in Farm
Bureau programs, activities, and services. Farm
Bureau's purpose is to increase total net income to its
members. Some of the many services available to
members are: 1) full time legislative staff (lobbyist) in
Tallahassee and Washington, 2) free accidental death
coverage for members, 3) marketing program fresh, top
quality produce and farm products are available through
the Farm Bureau, i.e. orange juice, fresh oranges, hams,
cheese, apples, jellies, etc., 4) discounts at Busch
Gardens, Coast-to-Coast Vision, Disney World, Sea
World, and Universal Studios, 5) pharmaceutical
program direct prescription and non-prescription items
at 30% discount, 6) insurance life, auto, Blue
Cross/Blue Shield, estate planning, 7) $500 reward
program theft, arson, vandalism, 8) information -
monthly state publication, fast facts, news releases, 9)
Women's program Kidney Fund, Youth Speech
Contest, Agri-Fest, county, district, and state information
meetings, 10) young farmer and rancher program open
to Farm Bureau members ages 18-35-outstanding Y&R
contest, discussion meet, district and state conferences,
11) youth county scholarships, Miss Florida Agriculture
Queen Contest, Youth Speech Contest, 12) Ag Advisory
Committee working directly with 15 major agricultural
commodity producer groups, and 13) Ag in the
Classroom workshops and mini-grants, etc.
Farm Bureaus Federated Together
Florida Farm Bureau Federation is comprised of
62 county units federated together. The Florida Farm
Bureau Federation federates itself with 49 other states
and Puerto Rico, to form the American Farm Bureau
Federation. The AmericanFarm Bureau Federation boast
of almost five million member families. The Farm
Bureau state office is located at 5700 S.W. 34th Street,
Gainesville, Florida 32608, telephone number (352) 378-
1321. The Florida Farm Bureau Federation president is
Carl B. Loop, Jr. from Jacksonville. President Loop is a
nurseryman by profession.
State Board of Directors
The 24-member State Board of Directors, which
meets every other month, is comprised of bona fide
farmers and ranchers from across Florida. They are
elected for a 2-yr term by other farmers and ranchers
within a three to four county district.
Farm Bureau Objectives
The purpose and objectives of Farm Bureau, as
previously mentioned, is to increase net income for its
members. This is done through legislative action,
service-to-member programs, and information and
education efforts. Farm Bureau is the "Voice of
Agriculture," representing every major commodity
produced commercially in our state. It is an organization
designed to provide a means by which farmers can do
together...the job that can't be done alone. It represents
the thinking and will of the "man on the land." It also
reflects the thinking of many non-farm people who share
basic conservative philosophy.
Farm Bureau activity is financed primarily
through members paying annual membership dues. The
average dues are approximately $35. A Farm Bureau
membership is a family membership.
Opportunity for all Ages
Farm Bureau attempts to provide opportunities
for involvement and participation by members of the
family, i.e. Women's Program and activities, Young
Farmer and Rancher Program, Scholastic Scholarships,
Youth Speech Contests, etc.
We are proud of Florida Farm Bureau and the
good it has done for its members and all agriculture for
almost 60 yr. Our many accomplishments and
achievements are proof of our success. Farm Bureau
continues to launch ahead and provide services to its
members through legislative, marketing, and other
programs designed to increase member's net income. It
can safely be said...Farm Bureau doesn't cost...it pays!
Role of Soil and Water Conservation of the Office of Agricultural Water Policy
David S. Vogel
The Department of Agriculture and Consumer
Services Office of Agricultural Water Policy (OAWP)
was created under state law to ensure that agriculture is
effectively represented in the development,
implementation, and evaluation of statewide water policy.
The primary purpose of this involvement is to participate
in water policy issues as they relate to agriculture, to
better communicate the needs of our industry to the
Legislature, appropriate agencies and the public, to
provide greater equity and certainty in water use,
allocation and planning processes, and to provide better
service to agriculture.
As a part of overall water policy coordination,
the OAWP has undertaken specific initiatives to establish
a process for agricultural regulatory streamlining, to
develop alternative approaches for achieving resource
conservation and protection through non-regulatory,
incentive-based strategies, to participate in South Florida
and Everglades ecosystem restoration activities to ensure
that restoration activities are conducted in a manner
consistent with sustainability of agriculture and resource
conservation, and to provide assistance to Soil and Water
Conservation Districts in carrying out conservation
activities at the local and watershed level. This process
includes participating in pilot demonstration projects for
regulatory streamlining, working with the agricultural
community and conservation partnership at the local level
to provide improved delivery of resource management
services to landowners, and establishing a problem-
solving approach to compliance and responding to
operational problems as an alternative to enforcement.
SOIL AND WATER CONSERVATION
The Soil and Water Conservation Program is
charged, under Chapter 582, F.S., to provide
administrative and technical support to Florida's 63 Soil
and Water Conservation Districts, including funding,
education, training and overall leadership. As a part of
the above water policy initiatives, the Soil and
D. S. Vogel, Soil and Water Conservation Administrator,
Florida Department of Agriculture and Consumer
Services, Soil and Water Conservation, Tallahassee, FL.
Manuscript received 31 March 1997.
Water Conservation Program has begun a revitalization
effort of the state's Soil and Water Conservation Districts,
and has redefined the scope and level of services
provided by the Department. In addition to ongoing
program assistance, the Department is introducing Soil
and Water Conservation Districts to new opportunities
for participation at the local level in critical agricultural
and water-related issues, including those described
During the past year, the Department began
efforts to expand the traditional conservation partnership
to reach out to additional agencies with jurisdiction in
water and land management. The Commissioner has
made new appointments to the Soil and Water
Conservation Council, and has reformed the role of that
advisory council in water- and conservation-related
issues. The program has also begun a process to better
integrate the local efforts of Soil and Water Conservation
Districts into state water management objectives, and to
provide greater access for agricultural producers and
landowners in water policy decision-making. In
partnership with the Florida Association of Conservation
Districts (FACD) and the U.S. Department of
Agriculture's Natural Resources Conservation Service
(NRCS), the Department is also assisting Soil and Water
Conservation Districts in their role as leaders in locally-
led conservation efforts under the 1996 Farm Bill, and in
building a local network around Soil and Water
Conservation Districts for better community-based
services to Florida's landowners in resolving natural
resource problems. These efforts are intended to expand
the scope of services already provided by Soil and Water
Conservation Districts (such as those activities related to
conservation tillage and field days) to provide additional
benefit to landowners and producers as they deal with
today's resource management requirements.
NEW OPPORTUNITIES FOR AGRICULTURE
Through efforts of the OAWP and other
divisions, the Department is working to expand services
to the agricultural community, and to create new
opportunities for locally-led, voluntary management
approaches to resolve agricultural and environmental
issues. This involves not only regulatory streamlining
and participation in water policy development, but
requires better local participation in land and water
management processes. These efforts represent new
opportunities for agriculture in that success will provide
greater flexibility and profitability for agricultural
producers. These also pose new challenges for
agriculture in that success will depend upon the
willingness of producers, public agencies, researchers
and educators to work together on new approaches. The
remainder of this presentation describes new approaches
under development or consideration.
Soil and Water Conservation Districts
(SWCDs) will play a critical role in this process. This is
because a cultural change is occurring in regulatory
agencies, encouraged by Congress and the state
Legislature, which has created a need for better local, or
community-based, services as a preferred alternative to
command-and-control regulation. SWCDs represent a
unique local perspective to resource management, and
have provided resource management services to
landowners for many years related to resource
conservation and protection on private lands. As we
explore alternative approaches to resource management,
especially non-regulatory choices, we must redefine and
revitalize the role of SWCDs to provide improved local
delivery of those alternatives.
Concurrent with these efforts, the 1996 Farm
Bill has created an opportunity to help rebuild local
networks around SWCDs through establishment of Local
Working Groups to implement the Farm Bill's
Environmental Quality Incentives Program. The
Department is cooperating with FACD and NRCS to
help SWCDs organize these local networks which will
provide the needed coordination at the local level as
resource management services are expanded beyond
Farm Bill programs.
A recent conference on Southeastern animal
agriculture explored issues associated with animal
production, and emphasized the need to develop and
apply new solutions to problems in animal waste
management, land management, grazing lands, and
farmland sustainability. Since that conference, we have
been working with producers and regulators to consider
how to apply a voluntary, incentive-based approach to
managing animal waste associated with dairy and poultry
operations. This process is a result of recognition that
traditional command and control regulatory programs are
not the most effective approach to working with people
to solve these types of problems. The voluntary approach
also maximizes the delivery of technical and financial
services to landowners, and applies resources more
directly to the problem. In response to a request for help
by animal producers the Department is taking a
leadership role in this process.
The primary components of a suggested
approach to animal waste management are as follows:
Voluntary participation. The best way to
ensure that improved practices become a part of a
producer's operation is to provide an opportunity for a
producer to make his or her business decision to adopt
such practices. This decision means that practices, or an
operational plan, belong to the producer, rather than to
government, and that government's role is to assist the
producer in achieving his or her goals. A voluntary
approach offers producers a choice of following the
regulatory path or an alternative which provides greater
Incentive-based participation. 'Producers
must be given proper incentives to change their practices
or to install technical solutions. These should include
appropriate relief from burdensome regulatory
requirements otherwise satisfied through adoption of
improved practices, including a presumption of
compliance with applicable water quality standards
through use of BMPs or other practices shown to be
effective in resource protection, and a reduction in
regulatory oversight and duplication. Increased and
simplified financial cost-share assistance should also be
made available as an incentive, as agencies should be
encouraged to apply funding toward putting practices on-
the-ground, as a substitute for traditional regulatory
program costs. An important part of the regulatory
incentive is the shift from regulatory inspections (often
involving multiple agencies) to a more local, non-
regulatory partnership where Department personnel and
Soil and Water Conservation Districts work with the
producer to track progress and assist with his or her plan,
replacing traditional regulatory inspections.
Research-based Best Management Practices
(BMPs) or Recommended Management Practices
(RMPs). Government, researchers and producers must
cooperate to develop and demonstrate improved practices
(BMPs), and to implement RMPs on a trial basis, to
provide a menu of sound management practices from
which to choose. These practices must meet two tests -
they must be effective in meeting the resource protection
objective, and they must be feasible (cost-effective) for a
producer to implement. By working with producers to
install practices, the partnership will be in a position to
identify where practices must be refined and where
additional research is needed (such as manure
management and land application to crops).
A problem-solving approach to compliance.
As described above, a local, non-regulatory partnership
will replace a regulatory or enforcement program to
ensure most effective adoption of improved practices.
Through this same partnership producers will be granted
flexibility while installing corrective actions where
problems are encountered. This involves employing the
same personnel who assist producers with their plan to
help resolve cases of actual or suspected non-compliance.
For example, where a problem (e.g., delay in a
producer's construction schedule, a structural failure,
poor housekeeping) is identified through routine on-farm
visits, a producer receives a recommendation for
corrective measures, and is allowed a specified period of
time during which no regulatory enforcement will occur
to work with partners (Soil and Water Conservation
Districts, NRCS, private consultant engineers) to solve
the problem. This provision, sometimes referred to as
safe harbor, facilitates greater efforts by producers to
identify problems, helps producers apply their resources
directly toward fixing the problem, and gives producers
credit for successful problem-solving. It also achieves
greater and more timely compliance with resource
protection objectives at a reduced cost to the public.
The Department is working with producers, the
Florida Farm Bureau, legislators, and the Department of
Environmental Protection to develop and implement this
approach. While specifics are uncertain as of this
writing, it is anticipated that voluntary, incentive-based
approaches will play a significant role in responding to
these animal waste management issues. Soil and Water
Conservation Districts will play a crucial role in this
process, by providing a local, non-regulatory partner
through which resource management services can be
delivered to landowners, and through which landowners
and producers can receive additional benefits in dealing
with regulatory requirements.
Role of Water Management Districts in the Production of a Wholesome Food Supply
Every three-and-a-half minutes, one acre of
Florida farmland is lost to development; and we are fast
becoming a state at risk of destroying what remains of our
rural heritage. A report prepared by American Farmland
Trust (1992) shows that Florida has the highest
conversion rate of farmland in the nation. This alarming
trend is being repeated in rural communities all across
America; but what I want to address is how we can -- and
must -- reverse that trend here in Florida.
Agriculture has always been, and always will
be, extremely important to our state. In 1995, Florida
farmers led the nation with 20 major agricultural products
including fruits, vegetables and houseplants. They
produce 75 percent of the nation's citrus, 10 percent of its
vegetables, and 25 percent of its domestic sugar supply.
Florida is the nation's 9th leading agricultural
state, with cash receipts totaling $6 billion annually.
Annual average farm employment exceeds 80,000
people, and farm-related economic activity generates
more than $18 billion each year.
But urban development and competition from
foreign imports are tightening the noose around Florida's
ag industry. It is therefore incumbent on all of us to
become partners with growers and producers, working
together to ensure agricultural sustainability and
I've been invited here today to talk about the
role of water management districts in the production of a
wholesome food supply. I can tell you what the districts
are doing to help keep agriculture alive and well in
Florida but as for the wholesome part, I'll have to leave
that up to the farmers!
Raised on a farm in rural Suwannee County, I've
come to learn a little bit about agriculture. I've seen the
ups and downs that farmers have faced over the years,
and understand their economic struggles. I also value the
quality of life found in our rural communities.
The Suwannee River region is one of the most
beautiful and unspoiled parts of Florida, so I know how
vital it is to protect and preserve our natural resources.
I believe the regional water management districts are
uniquely qualified to lead the way in finding creative and
J.A. Scarborough, Executive Director, Suwannee River
Water Management District, Live Oak, FL. Manuscript
received 12 March 1997.
cost-effective ways to help meet the needs of local
farmers and at the same time fulfill the districts' mission.
And what exactly is our mission?
When the districts were created by the
legislature in 1972 under the Florida Water Resources
Act, we were told to control two things: flooding and
water supply. Eleven years later the legislature gave us
stormwater permitting responsibilities. The State also
has expanded our duties to include wetlands permitting,
water well construction permitting, and land acquisition
Critics argue that water management districts
have grown too big, and we've often come under fire for
branching out into programs that some consider to be
outside of our primary purpose. Maybe we have grown
and stretched beyond our original scope. But as times
and circumstances change, so do the ways by which we
must address our state's complex environmental and
The role of water management districts today
and in the future will require a new way of operating,
which I can sum up in one word: partnerships. It will
mean shifting away from traditional regulation to a more
cooperative spirit between government and those who are
governed. It will mean streamlining the permitting
process, and replacing penalties with incentives as the
preferred means of encouraging stewardship and
We have a better understanding today than we
did in 1972 about how land use and water use are closely
linked. We've discovered that good water management
requires good land management -- you cannot separate
the two. Improved technology now offers us solutions
we've never had before, especially in the field of
Central to agricultural sustainability is the
availability of water. The districts' role as we enter the
21st century will be the same as it's always been -- to
determine how much water is available for use, to protect
the quality of that water, and to help develop more
efficient methods of conservation and distribution.
What will that mean to the farmers?
Right now, agricultural irrigation accounts for
nearly half (49.7%) of all freshwater withdrawals. In the
40-year period between 1950 and 1990, agricultural
water withdrawals jumped by 915% statewide:
1950 375 mgd
1970 2100 mgd
1990 3805 mgd
I am happy to report, however, that total
freshwater withdrawals decreased by 281 mgd between
1990 and 1995, from 3805 mgd to 3524 mgd, according
to preliminary figures compiled by the US in Tallahassee.
This is due to a number of factors, including the use of
more efficient irrigation techniques, and a willingness to
rely less on freshwater and more on alternative sources.
The water management districts are committed to
working with agriculture to find ways to achieve even
Each district is in the process of establishing
minimum flows and levels for the ground and surface
water resources within its region. This means calculating
how much water flows in our rivers, lakes, streams and
aquifers during various times of the year, and determining
how much water can be withdrawn for human use
without causing harm to the natural systems. The
districts will use these calculations as part of the basis for
reviewing requests for water use permits. We're also
supporting legislation that would allow us to issue
long-term consumptive use permits, valid for 20 years, to
applicants who use conservation techniques or who rely
on alternative water sources.
In response to recommendations made by the
Water Management District Review Commission in late
1995, the districts, along with the Florida Department of
Environmental Protection (DEP), Florida Department of
Agriculture and Consumer Services (DACS), and the
Florida Game and Fresh Water Fish Commission
(FGFWFC), signed a memorandum of understanding to
work together to streamline, consolidate and simplify the
existing agricultural permitting process. We've all agreed
to develop voluntary, incentive-based alternatives to
traditional permitting for agricultural activities, and we
formed the Agricultural Regulatory Streamlining Group
(ARSG) to accomplish these tasks.
Currently the group is evaluating the Environmental
Resource Permitting (ERP) process as it relates to
agricultural activities. The group is working to: clarify
existing statutory exemptions; develop more consistent
rule exemptions; develop streamlined (Notice General)
permits for specific ag activities under ERP; and make
it easier to obtain and comply with ERP permits through
1) permit consolidation, 2) team permitting, 3) one-stop
The group's intent is to create more consistency
and uniformity in the statewide ERP agricultural
program, while at the same time allowing for some
variation based on regional differences in water
resources, agricultural practices and water management
district priorities. Throughout this process, the group
will seek input from the ag community around the state.
The districts also are expanding their efforts to
develop alternative sources, especially in regions
experiencing declining or deteriorating freshwater
supplies. Farmers are encouraged to use desalinated or
reclaimed water, which are highly suitable for agricultural
use, in combination with more efficient irrigation
methods. Four of the five districts offer a matching grants
program to assist agriculture and other users in
developing alternative water supplies.
Working together hasn't always been easy, but
I think we're all getting better at it. The level of trust and
communication between the districts and the agricultural
community is good and getting better, because we realize
we have more to gain as partners than as adversaries.
Each time we work through a challenge and can
point to a success story, we are more encouraged about
our chances to resolve future differences. Let me share a
few of those success stories.
For years, farmers in Indian River County had
depended on the Blue Cypress Water Management Area
to provide surface water for irrigation and freeze
protection, and as a place to store floodwater from their
lands. The area also was designed to divert agricultural
runoff from the rest of the St. Johns Marsh.
But the area was found to be a nesting site for
the endangered Everglades snail kite and its primary food
source, the freshwater apple snail. Officials were
concerned that water withdrawals for irrigation and freeze
protection might impact the kites and their only food
source. They were also concerned about the potential
affects of farm runoffon the water quality of the marsh.
At the request of the U.S. Fish & Wildlife Service, a
management plan was issued to control water
withdrawals from the area.
This created hardship for local farmers and
citrus growers, and hard feelings between them and
government. In an effort to meet the needs of farmers and
still protect the endangered kites, the St. Johns River
Water Managmement District arranged meetings between
the state and federal agencies, University of Florida fish
and wildlife researchers, and farmers and growers.
The result was a series of studies followed by
recommendations for alternative water sources and
agricultural runoff arrangements. It was also decided that
growers could conduct short-term freeze protection
withdrawals without harming the ecosystem.
Another example is the Southwest district,
which has been working to improve relations with the ag
community through its Agriculture Surface Water
Management (AGSWM) program that offers farmers an
alternative to formal permitting. The St. Johns and
Suwannee districts also have similar programs in place.
In the Middle Suwannee basin, where we've
recently seen an increase in nitrates in our rivers and
springs, the Suwannee district is working with the
Natural Resources Conservation Service (NRCS) on a
PL-566 cost-share program to install best management
practices at 44 local dairy operations. We were able to
add $1.2 million in SWIM (Surface Water Improvement
and Management) dollars to NRCS funding for the
installation of site-specific best management practices
(BMPs) which will provide economic benefits to farmers
as well as benefits to the environment.
Most of my remarks have been directed toward
the dairy, field crop and citrus producers, but I don't want
to fail to mention what we're doing to assist another very
important segment of the agriculture industry --
A record $73 million in aquaculture products
was sold in 1993. The aquaculture industry depends
more than anything else on clean water, and the districts
are working to ensure that our coastal areas have good
water quality to support them.
We continually monitor inland and upstream
activities to make sure they don't adversely impact the
water quality in downstream shellfish harvesting areas.
Where we find problems, we try to help fix them. A good
example is the wastewater treatment project for the Town
of Suwannee in Dixie County.
In 1991, the U.S. Food and Drug
Administration (FDA) ordered the closure of Suwannee
Sound for shellfish harvesting, due to high bacterial
contamination caused by poor septic systems in theTown
of Suwannee. To help preserve and protect the area's
water resources and the local shellfish industry, the
District allocated $25,000 for a detailed feasibility study
that addressed the town's wastewater treatment needs.
The District also helped local city and county officials
obtain $8.4 million in federal grants and loans, and
groundbreaking on the project took place in June 1996.
The Suwannee district also recently agreed to
purchase Atsena Otie island off of Cedar Key. Residents
there were concerned that planned development of the
island would create water quality problems, and threaten
the lucrative local shellfish industry. The district agreed
to help Levy County seek grant funds for the land
purchase and, if none were available, to acquire the land
until such time as the county could purchase it.
Should the districts be in the real estate
business? When the end result is the protection of our
natural systems, I would say the answer is a definite "yes."
Should we help local governments to design stormwater
plans? When we have the financial and technical means
to assist those who do not have adequate resources, again
I would say the answer is yes.
Turning to water quantity, Levy County farmers
in our district recently agreed to participate in a voluntary
pilot project to install time totalizers to measure
agricultural water use. Until now, the Suwannee district
has depended on a voluntary self-reporting system which,
quite frankly, has not been very successful in terms of
willing or consistent participation. The return rate on our
twice-yearly water use surveys has been low, about
17%-20% District-wide. We're now looking at the
possibility of requiring the use of more traditional means
of reliable data collection.
The only available statewide water use numbers
are the ones compiled every five years by the U.S.
Geological Survey, and those figures alone are not always
a true reflection of agricultural water use. Climate
conditions, gain or loss of cropland, and even the
definition of what constitutes "agricultural" use tend to
blur the picture somewhat.
Collectively, the districts must find ways to:
use more accurate, consistent reporting and collection
methods; eliminate some categories that fall under the
definition of agricultural use"; clarify the "gray areas" in
our permitting rules, and figure out how to factor in all of
the variables. We may discover that farmers are using
less water than we thought. Or some farmers may
discover they are using more water than they need for a
crop, and as a result will look for more efficient and
economical ways to irrigate.
Finally, the water management districts can and
should support state and local efforts to preserve
agricultural lands.This can be done through: conservation
easements and PDR (purchase of development rights)
programs; Blue Belt laws or other tax incentives; and
creation of voluntary agricultural districts
These programs offer financial relief to
cash-strapped farmers who might otherwise have to sell
their land to developers. It also keeps valuable and
productive agricultural lands under private ownership
and on county tax rolls.
Keeping land in agriculture and open spaces is
good for the environment and the economy. It also
provides many environmental benefits. Unpaved lands
serve as aquifer recharge areas, floodwater storage areas,
and habitats for plants and animals. They serve as buffers
between urban development and the state's natural areas,
providing scenic and open spaces enjoyed by outdoor
recreationists and ecotourists.
The 1996 Farm Bill has made millions of
dollars available through a new Farmland Protection
Program that matches federal funds with state and local
money for the purchase of conservation easements. Last
year the St. Johns district received $400,000 to arrange
a conservation easement in Osceola County as part of the
Upper St Johns project Other districts will likely submit
their own proposals in the future.
During the 1980s, a poll was conducted by
American Farmland Trust and the Soil and Water
Conservation Society to find out what Americans thought
about the need to preserve farmland. Urban residents,
farmers and rural landowners all expressed
overwhelming support for farmland protection programs:
73% of the general public said that good farmland should
not be used for houses and industry; 77% of the general
public agreed on the need for a government policy to
protect Florida's best farmland from urban growth; and
65% of the general public supported providing economic
incentives to farmers to keep their land in farming.
The reason is simple: American consumers still
want to see home-grown food on their tables. We know
that U.S. farmers must meet the highest food production
standards in the world. We want to be able to enjoy juicy
Florida oranges, fresh Plant City strawberries, sweet
Zellwood corn and North Florida potatoes. I can't
imagine a summer picnic without iced-cold watermelons,
boiled peanuts, or that favorite of all Southern dishes --
fried, baked, or barbecued chicken-- all of which are
produced right here in Florida.
We don't want to see our rural areas or way of
life disappear. Agriculture is an important part of our
heritage and of our future.
Florida Department of Agriculture and Consumer
Services. 1995. Agricultural Facts.
Florida Department of Environmental Protection. 1997.
Draft: Strategic Assessment of Florida's
U.S. Geological Survey, Tallahassee, FL. 1997.
Preliminary Draft: 1995 Annual Water Use
Florida Farm Bureau, Florida Agriculture. Sept.-Dec.
1995; Feb., Mar., May, Oct. 1996.
Gainesville Sun, February 23, 1997.
American Farmland Trust. June 1992. Florida's Growth
Management Plans: Will Agriculture
Survive? A Report on the Impact of Continued
Population Growth on Florida's Farmland.
Role of Conservation Tillage in Production of a Wholesome Food Supply
*Raymond N. Gallaher and Larry Hawf
Erosion of farmland continues to be a major
conservation issue facing the United States today.
Agricultural lands can lose many tons of valuable topsoil
to wind and water erosion, as much as 20 large
truckloadsyr from an average-sized farm. This much soil
can change the course of a river, altering ecosystems by
destroying fish spawning areas and preventing light from
reaching aquatic life. In addition, eroded soil carries
nutrients, pesticides, and other harmful chemicals into
rivers and streams (Gallaher and Lauret, 1983)..
Most of the Southern states have a high average
annual rainfall and are subject to flash flooding. Erosion
from rainfall is a major problem. While the flat lands of
some areas such as in Florida, are less likely to erode,
sandy soils and heavy rainfalls make erosion and related
water quality problems a concern for farmers to deal
with. A Best Management Practice, or BMP, which
reduces soil erosion and protects water, while at the same
time increasing land productivity and conserving fuel, is
conservation tillage. The objectives of this paper are: 1)
to provide a review of conservation tillage management,
2) to present information on new emerging
biotechnologies and equipment impacting conservation
tillage, and 3) to provide information on changing trends
in farmer adaptation.
Conservation tillage Any tillage and planting system
that covers 30% or more of the soil surface with crop
residue, after planting, to reduce soil erosion by water.
Where soil erosion by wind is the primary concern, any
system that maintains at least 1,000 lb/a of flat, small
grain residue equivalent on the surface throughout the
critical wind erosion period (Anonymous, 1996a). No-
till, no-tillage, ridge-till, mulch-till, row-till (in-row
subsoil no-tillage; strip-tillage), minimum tillage, etc. are
examples (Anonymous, 1996b).
No-till Planting or drilling is accomplished in a narrow
'R.N. Gallaher and L. Hawf, 'University of Florida,
Institute of Food and Agricultural Science, Gainesville,
FL, and 2Monsanto Chemical Co., Sasser, GA.
Manuscript received 10 April 1997. *Corresponding
seedbed or slot created by coulters, row cleaners, disk
openers, in-row chisels, or roto-tillers. The soil is left
undisturbed from planting to harvest except for nutrient
or pesticide injection. Weed control is accomplished
primarily with herbicides. Cultivation may be used for
emergency weed control (Anonymous, 1996a; 1996b).
Ridge-till Planting is completed in a seedbed prepared
on ridges with sweeps, disk openers, coulters, or row
cleaners. The soil is left undisturbed from planting to
harvest except for nutrient injection. Residue is left on
the surface between ridges. Weed control is
accomplished with herbicides and/or cultivation. Ridges
are rebuilt during cultivation (Anonymous, 1996a;
Mulch-till The soil is disturbed prior to planting.
Tillage tools such as chisels, field cultivators, disks,
sweeps, or blades are used. Weed control is
accomplished with herbicides and/or cultivation
(Anonymous, 1996; 1996b).
Strip-till (Row-till or in-row subsoil no-till) Planting is
accomplished by use of a subsoil unit following in
sequence after the no-tillage coulter. Subsoil depth is
extended 2-in below the average hardpan layer. The
subsoil slot is closed immediately with coulters or other
appropriate devices following the subsoil units and in
front of the seed placement attachments. Approximately
3- to 6-in of bare soil seedbed is prepared over the row
with minimum disturbance of crop residue between the
rows. Injection of fertilizers and pesticides can be
accomplished in the row area during the planting
operation. The soil is usually left undisturbed from
planting to harvest. Weed control is accomplished with
herbicides and/or cultivation (Anonymous, 1996b;
Gallaher and Lauret, 1983).
Reduced tillage/minimum tillage Tillage types that
leave 15-30% residue cover after planting or 500 to 999
lb/a small grain residue equivalent throughout the critical
wind erosion period (Anonymous, 1996a; 1996b;
Gallaher and Lauret, 1983; Gallaher, 1980).
Conventional tillage Tillage types that leave less than
15% residue cover after planting, or less than 500 lb/a of
small grain residue equivalent throughout the critical
erosion period. These types generally involves plowing
or intensive tillage where seedbed preparation is by use
of cultivation equipment such as harrows, moldboard
plows, offset harrows, subsoilers and/or rippers
(Anonymous, 1996a; 1996b; Gallaher and Lauret, 1983).
Multiple cropping Intensive cropping systems where
two or more crops/yr are grown on the same land area
(Gallaher and Lauret, 1983).
Double cropping A form of multiple cropping where
two crops are grown on the same land area in one yr,
usually in sequence, like wheat (Triticum aestivum L.)
followed by soybean (Glycine max [L.] Men-) (Gallaher
and Lauret, 1983).
CONSERVATION TILLAGE AND WATER
Since conservation tillage disturbs less soil than
conventional tillage, wind and water erosion is reduced
(Langdale and Leonard, 1982). Conservation tillage is
usually practiced in combination with multiple cropping
where the second crop is planted in the residue of the first
crop. This residue acts as a mulch to conserve moisture
and protect soil (Gallaher, 1977).
THE BENEFITS OF CONSERVATION TILLAGE
Conservation tillage is well-suited to the South,
especially in Florida's sandy and medium-textured soils.
In addition to soil and water conservation, this fanning
method has several other benefits (Gallaher and Lauret,
1983): 1) fuel is saved because fewer trips over a field
are necessary; 2) higher yields often result due to
compatibility with multiple cropping, 3) land use is
intensified since it is possible to plant a second or third
cash crop without delay of elaborate seedbed preparation;
4) lower-cost land can be farmed because it is possible to
plant row crops on sloping pasture land; 5) soil structure
is improved near the soil surface due to organic material
in residue, particularly if burning of residue is required
under conventional tillage; 6) time and labor are saved
throughout the season because of fewer field operations;
7) machinery costs are lower, since only one machine is
required; and 8) stress of drought is reduced because a
more vigorous root system is fostered, especially with in-
row subsoil no-tillage systems (Gallaher, 1980; Gallaher
and Lauret, 1983; Langdale and Moldenhaure, 1995;
The risk that weed control will not be effective
is a major drawback associated with conservation tillage.
Herbicides often developed for use in conventional tillage
have been adapted for control of grass and broadleaf
weeds in conservation tillage management. Only in the
last few years have new herbicides been developed
specifically for conservation tillage systems. These new
herbicides have lessened the weed control problem to a
large extent Other disadvantages of conservation tillage
are: 1) herbicides necessary to make conservation tillage
a success may be costly; 2) some pests can be more
troublesome because crop residues are a haven for
breeding insects and diseases. ( A spraying program may
have to accompany the practice of conservation tillage in
some instances); and 3) if farmers do not have up-to-date
equipment they must plant about 10% more seed since
seed may not be uniformly buried in rough seed beds.
However, subsoiler attachments can alleviate this
problem, as well as new planters specifically designed for
HOW TO DO IT
Careful management of fertilizer is essential for
the success of most conservation tillage cropping systems
because, in most cases, fertilizer lies on the soil surface,
not in it. However, with in-row subsoil planters it is
possible to have greater precision of placement of
fertilizers in the soil and at specific distances from the
seed being planted. When legumes like soybean and
peanut (Arachis hypogaea L.) are part of a multiple
cropping operation, less fertilizer may be needed because
the legume creates its own N, enriching the soil for the
next crop as well. These legumes may also obtain
recycled nutrients from the previously fertilized crop in
the sequence. Data shows that many multiple cropping
systems, depending on the soil type, can be fertilized
effectively with a one-time application of lime, P and K
in the fall. In extremely sandy soils, more fertilizer may
need to be applied with the second crop as well.
Growers who opt for a conservation
tillage/multiple cropping system sometimes need to step
up their application of pesticides. The reduction of
intervals between crops may not leave enough time for
roots to decompose and cause root pests to flourish. On
the other hand, selecting some cropping sequences may
result in reductions of crop pests (Gallaher et al., 1988).
Crop rotations have been used historically and continue
to be used today to aid in control of pests (Gallaher et al.,
1988; Gallaher et al., 1991; McSorley and Gallaher,
1994; 1995). Wise use of crop management strategy can
result in reduced need of pesticides if proper selection of
herbicides, insecticides, and nematicides are chosen.
CROPS FOR CONSERVATION TILLAGE
Soybean planted in small grain residue is the
most widely used no-tillage double cropping system in
the Southeast, and probably the world, among agronomic
crops. In some areas of the United States, more than
50% of corn (Zea mays L.) and soybean are grown by
conservation tillage (Anonymous, 1996). Generally
speaking, the most common crop combinations are: 1)
soybean, grain sorghum (Sorghum bicolor [L.] Moench),
and forage crops following small grain (for grain); 2)
field and pasture crops following corn; 3) corn, grain
sorghum, and soybean following green manure crops, like
vetch (Vicia villosa L.), lupin (Lupinus angustifoilus L.),
crimson clover (Trifolium incarnatum L.), and rye
(Secale cereale L.); and 4) corn, soybean or grain
sorghum following temporary winter pasture, like rye, oat
(Avena sativa L.), and ryegrass (Lolium spp.) (Gallaher,
1980; Gallaher, 1981a; 1981b; Gallaher, 1989.
Experimentation and some application is on-going with
many other agronomic and horticultural crops such as:
tobacco (Nicotiana tabacum L.), cotton (Gossypium
hirsutum L.), squash (Cucurbitapepo L.), okra (Hibiscus
esculentus L.), bushbean (Phaseolus vulgaris L.), sweet
corn, and cowpea (Vigna unguiculata [L.] Walp.).
The availability of planting equipment designed
to operate under unplowed stubble or mulched conditions
is another reason for the rising popularity of conservation
tillage. Several makes of planters and drills are now on
the market A good planter and associated tractor can be
adapted so that application of herbicide(s), insecticide,
and fertilizer can be performed in a single pass over the
field. Even with all the successes with conservation
tillage there may be times when the moldboard plow will
still have to be used. Past and present research indicate
that elimination of conventional tillage may be possible,
particularly with the in-row subsoil (row-till or strip-till)
equipment. If tillage does become necessary, it is
possible to plow part, say 25%, of the area over the row
each year. Strip-tillage allows seedbed preparation over
the row, while allowing crop residue to remain for
conservation uses between the rows to offset the need to
NEW BIOTECHNOLOGIES AND EQUIPMENT
New discoveries in biotechnology are quickly
providing cultivars of crops that have been altered to be
resistant to herbicides and other chemicals. New
biotechnologies to be discussed in this presentation will
include: 1) Roundup Ready (RR) crops (Woodruff, 1997)
such as soybean and cotton, 2) Liberty Link corn, 3)
Bacillus thurgiensis (Bt) technology, etc. Additionally,
this presentation will include information on new
equipment inventions, such as various versions of the
hooded sprayer that allows the safe and effective use of
previously unusable herbicides. These new and emerging
technologies are having a significant impact on the ability
to use conservation tillage management on previously
difficult situations and thus providing for the conservation
of our natural resources and a greater sustainable
agriculture for the future.
ADOPTION OF CONSERVATION TILLAGE
It has been reported that there are 149.7 million
a of highly erodible land in the U.S. Of this acreage,
indications are that 127.2 million acres are currently
reported as "adequately treated." Total U.S acreage in
crop production was up in 1996. Total cropland planted
in 1996 was 290.2 million a, compared to 278.6 million
in 1995. The increased cropland acres planted in 1996
likely reflects land returned to production following the
end of commodity-based, government set-aside programs.
Conventional-till gained 1.9 million a for a total
of 115.5 million a in 1996. Over the last 8-yr,
conservation tillage systems have experienced
phenomenal growth. For example, in 1989 the U.S. had
71.7 million planted a of conservation tillage (25.7% of
U.S. total). In 1996 conservation tillage had increased
to 103.8 planted a (35.7% of U.S. total). The upward
trend continued in 1996 over 1995. In 1996, no-till
increased 2 million planted a for a total of 42.9 million a.
Mulch-till gained 2.9 million a for a total of 57.5 million
a. Ridge-till was unchanged at 3.4 million a. Reduced-
till gained 4.7 million a for at total of 74.8 million a.
Two of the Southern states are among the top five no-till
states in the U.S., based on % of acres planted to no-till
in 1996. These states are, number one Kentucky with
51% and number three Tennessee with 44%. The
Southern states had a total of over 17.2 million
conservation tillage planted a in 1996 (Anonymous,
1996a). New discoveries in biotechnology, equipment,
and production research, education and communication
efforts, and the continual improvement in the U.S.
agricultural infrastructure, among all those involved with
the production of a wholesome food supply, should keep
this upward trend of conservation tillage planted acreage
on the move.
Conservation tillage technology advancements
are not only on the move in the U.S.A. but are also
rapidly advancing in other parts of the world (Gallaher,
1981a; 1981b; 1989; Landers, 1996). One example is
the Brazil, where in 1981 there were only a few thousand
a ofno-tillage planted crops (Gallaher, 1981 a) and today
there are almost 14 million planted a (Landers, 1996).
This same phenomenon is occurring in Canada,
Australia, Europe, Africa, Asia, etc. As in the U.S.A.,
conservation tillage farmers all over the world are living
in harmony with their environment and doing their part to
not only provide a wholesome food supply for people
today but also are providing for a more sustainable
agriculture for future generation to come.
HOW TO GET HELP
Many types of conservation tillage require an
innovative, highly skilled, and informed individuals who
want to make the management work on their farm.
Therefore, if you are considering conservation tillage,
learn before, not after you make mistakes. Attend short
courses, conferences, field days, and demonstrations. It
is best to test conservation tillage, especially no-tillage,
on a small scale acreage first. The USDA-Natural
Resource Conservation Service (NRCS) in your district
may know of conservation cost-share programs for small-
scale learning. The USDA-NRCS can help with farm
plans that include conservation tillage. The Farm Service
Agency may be helpful as well. Major companies who
manufacture conservation tillage equipment or make and
sell products for conservation tillage management of
weeds, insects, and diseases in cropping systems have
college-trained personnel. These individuals can also
provide expertise to those beginning into conservation
tillage as well as those who are established conservation
Because planning is so important for successful
conservation tillage management, you will benefit from
guidance of your county Extension agent. The agent can
advise you of the conservation tillage/multiple cropping
system best suited to your land and crops. Several
publications related to conservation tillage and multiple
cropping are available through the county Extension
Conservation tillage is a BMP that guards water
quality and controls erosion as well. For maximum
conservation of soil and water, you may want to develop
a conservation plan ofBMPs that includes a conservation
tillage/multiple cropping system. Your USDA-NRCS
can assist in developing such a plan. Others in the
farming infrastructure of research and extension can help
solve and provide answers to make your operation
successful. Industry is indispensable in this infrastructure
as well. The seed, chemical, fertilizer, etc. industries
have products and expertise to aid in your success with
conservation tillage/multiple cropping systems. Utilizing
knowledge from all of the partners involved with
production of a wholesome food supply, while adopting
conservation tillage management, will help ensure a
greater sustainable agriculture for future generations.
Anonymous. 1996a. National Crop Residue Management
Survey. Conservation Tillage Information
Center, West Lafayette, IN.
Anonymous. 1996b. Glossary of Soil Science Terms.
Soil Sci. Soc. Amer., Madison, WI.
Gallaher, R.N. 1977. Soil moisture conservation and
yield of crops no-till planted in rye. Soil Sci.
Soc. Amer. J. 41:145-147.
Gallaher, R.N. 1980. Multiple cropping minimum
tillage. MMT-1. Florida Coop. Extn. Serv.,
IFAS, Univ. of Florida, Gainesville, FL.
Gallaher, R.N. 1981a. Plantio direto. pp. 101-109. In
Proceedings Anoiado I Encontro Nacional de
Direto. Cooperative Central Agropecuaria,
Campos Gerais LTDA, Ponta Grossa, Parana,
Gallaher, R.N. 1981b. Cosechas multiples, labranze
minima. Gaceta Agronomica. 1(1):57-63.
Gallaher, R.N. 1989. Crop development and soil
management in succession multicropping
minimum tillage systems. pp. 6-1 to 6-24. In
Proceedings of the International Seminar on
Yield Losses Due to Continuous Cultivation of
Major Economic Crops. Food and Fertilizer
Technology Center for the Asian and Pacific
Region (FFTC/ASPAC), and Development
Administration, Suweon, Korea.
Gallaher, R.N. 1991. Nematode densities associated
with corn and sorghum cropping systems in
Florida. Suppl. J. Nematol. 23:668-672.
Gallaher, R.N., D.W. Dickson, J.F. Corella, and T.E.
Hwelett. 1988. Tillage and multiple cropping
systems and population dynamics of
phytoparasitic nematodes. Ann. of Appl.
Gallaher, R.N., and M.F. Laurent. 1983. Minimum
tillage: pollution solution. Best Management
Practices SP21. Univ. of FL, Inst. Food & Agr.
Sci., Gainesville, FL.
Landers, J.L., (ed.) 1996. Fasciculo de Experiencias de
Plantio Direto no Cerrado. Association de
Plantio Direto no Derrado, A.P.D.C. Lagos
Sul, Brasilia-DF, Brazil.
Langdale, G.W., and W.C. Moldenhauer (eds.). 1995.
Crop residue management to reduce erosion and
improve soil quality Southeast. USDA-ARS
Conservation Research Report Number 39,
January 1995, Secretary of Agriculture, USDA,
McSorley,R, and RN. Gallaher. 1994. Effect of liming
and tillage on soil nematode populations under
soybean. Soil Crop Sci. Soc. Florida Proc.
McSorley, R., and R.N. Gallaher. 1995. Effect of yard
waste compost on plant-parasitic nematod
densities in vegetable crops. Suppl. J.
Woodruff, J.M. 1997. RR soybean variety and drill
planting. Oilseed Reporter 7(1):8.
Sustainable Agriculture in Production of a Wholesome Food Supply
E.T. York, Jr.
I have been asked to discuss the topic of
agricultural sustainability and the global challenge of
meeting the wholesome food supply needed for an ever-
Sustainability concepts have been applied in
some disciplines for many years. However, the term
"sustainability" came into widespread use within the past
5 to 10 years when it began to be applied primarily to
Third World development issues.
During the 1980s there emerged a growing,
global concern over the manner in which many of the
earth's natural resources were being used and whether,
with such usage, the needs of a steadily increasing
population could be sustained. To put this concern in
perspective, however, it should be noted that the 20th
century has seen remarkable progress in all areas of
human endeavor, such as education, medicine, industry,
commerce, and agriculture. These advances have
resulted in better living conditions, increased life
expectancy, better educational opportunities and higher
literacy rates, improved food supplies, better nutrition,
and a general improvement in the quality of life for many
(but not all) people around the world.
There is growing concern, however, that this
progress may not be sustainable because, in making these
advances, we have exhausted inordinate amounts of
nonrenewable resources; we have used, misused, and
abused many of our renewable natural resources; and we
have contributed to the degradation of many facets of our
environment in ways that could jeopardize the very future
of humankind itself.
While reflecting on this progress, it should be
noted that millions of people around the world have not
enjoyed the advances and improvements in living quality
to which I have alluded. The global community is,
therefore, faced with the challenge of trying to include
those who have been largely by-passed by human
progress while, at the same time, sustaining the progress
that has been made by others. Moreover, there is need to
do this in ways that do not limit the ability of future
generations to enjoy similar progress.
E.T. York, Jr. Distinguished Service Professor, Emeritus,
University of Florida, Gainesville, FL. Manuscript
received 26 March 1997.
Commission On Environment And Development
This challenge was the motivation for the
United Nations to establish the Commission on
Environment and Development in 1983. This
commission, chaired by Prime Minister Brundtland of
Norway, was charged with the task of formulating long-
term strategies to achieve sustainable global development
by the year 2000 and beyond. In its 1987 report (Anon.,
1987), Our Common Future, the commission defined
sustainable development as "development that meets the
needs of the present without jeopardizing the ability of
future generations to meet their needs."
In applying these sustainability concepts to
agriculture, a panel of the commission said, "Enduring
food security will depend on a sustainable and productive
resource base. The challenge facing governments and
producers is to increase agricultural productivity and thus
insure food security, while enhancing the productive
capacity of this natural resource base in a sustainable
The panel suggested the magnitude of this
challenge in these words: "The next few decades present
a greater challenge to the world food systems than they
may ever face again. The effort to increase production in
pace with unprecedented increase in demand, while
retaining the essential ecological integrity of food
systems, is colossal, both in its magnitude and
complexity. Given the obstacles to be overcome, most of
them man-made, it can fail more easily than it can
succeed" (Anon., 1987).
Trends In Agricultural Production
Given the emphasis that the commission places
on increasing global food production to meet growing
needs, what about current trends in agricultural
production and prospects for meeting such greater needs?
Before World War II, most of the increase in
global agricultural production occurred as a result of
expanding cultivated areas as more production was
needed, more land was brought into cultivation.
The post-World War II period has seen an
unprecedented growth in agricultural production. On a
global basis, agricultural output has grown at a rate of
approximately 2.5% per year. Moreover, this growth in
global production has generally exceeded the growth in
population, resulting in an overall increase in per capital
food production of approximately 0.6% annually between
1950 and 1986.
This growth can be attributed not so much to an
expansion in the total area under cultivation but rather to
a greater productivity resulting from the development and
application of improved technology. This improvement
in agricultural output was made possible not only by large
production increases in industrialized regions, including
Western Europe, North America, and Australia, but also
in many Third World countries, especially Asia.
Hunger And Malnutrition Remain Serious Problems
With such growth, one might assume that global
food supplies would be adequate; however, such statistics
are often misleading. Africa, for example, has not shared
in this improvement. In fact, for the past 20 yr or so, per
capital production of food in Africa has declined at the
rate of approximately 1% annually.
While average production in the other major
regions of the world may reflect significant progress,
there are extensive areas in Asia and Latin America that,
for various reasons, have not enjoyed the progress
necessary to accommodate basic food requirements.
Moreover, even in regions that normally have good
supplies, temporary shortages and even famine can result
from war, floods, droughts, earthquakes, and other
disasters that disrupt production.
The World Bank estimates that more than 700
million people, about one-third of the developing world
population, do not receive enough calories for an active
working life. Part of this difficulty grows out of a lack of
purchasing power, which limits the ability of many of the
world's hungry and malnourished to buy the food that is
Future Prospects For Agricultural Production
If the sort of spectacular growth that has
occurred in agricultural production in the last half of the
20th century has fallen short of meeting global food
needs, what are the prospects of doing better of more
adequately accommodating these needs?
Current trends in food production do not offer
great promise in this regard Indeed, it is readily apparent
that growth in agricultural production in much of the
Third World is slowing significantly. For example, in
four of the six developing country regions (North and
sub-Saharan Africa, and South and West Asia), the
annual growth in per capital food production was less
during the last 9 yr (1977-86) of 1950 to 1986 than for
the entire 36-year period. These data suggest that, in
recent years, significant parts of the developing world are
falling behind in efforts to meet growing needs for
Moreover, since 1986 there have been some
sharp reversals in gains in cereal production. With only
slight increases in cereal production globally in 1985-86,
there were major declines in production in 1987-88.
Brown (1988) indicates that in the mid-1980s, grain
production plateaued in some of the world's most
populous countries India, Indonesia, Mexico, and China
- countries that earlier had enjoyed tremendous growth in
Herdt (1988) and others have pointed to the
closing gap between actual national yields of major food
commodities and potential yields, as reflected by work at
research stations. In tests at the International Rice
Research Institute in the Philippines, maximum yields of
rice (Oryza sativa L.), for example, have apparently not
increased since 1965.
Many believe that the Green Revolution, which
saw remarkable progress in cereal production in the last
two to three decades, has essentially runs its course, and
future advances in agricultural output will depend on
further significant breakthroughs in the development of
production technology through research.
Concerns Over Future Prospects
These trends are not encouraging. Moreover,
there are ominous dark clouds on the horizon that suggest
the problem could become much worse. Below is some
evidence to support this contention.
The demand for food is steadily growing as
some 90 million people are added to the global
population annually. Significantly, more than 90% of this
growth is occurring in the developing world, where
serious problems of hunger and malnutrition already
Another cause for concern is the growing
difficulty in expanding areas of productive arable land
well suited for cultivation. It is estimated that from 1975
to 2000, the area of cultivated land globally will expand
only 4% while global population will increase
Environmental and Natural Resource
A third and most disconcerting concern related
to agriculture's ability to achieve continued improvement
in productivity is the belief by many that we are, in fact,
compromising the ability of future generations to meet
their food needs by our current misuse of the natural
resources on which agriculture depends.
Nothing in recent years has captured the
attention and generated the concern of the world
community more than the evidence of serious global
environmental and natural resource degradation
problems. These problems include the rapid destruction
of tropical forests, the increasing concentration of
atmospheric CO, levels, and what some believe is the
related global warming trend; the destruction of the ozone
layer, as well as ozone pollution problems near the earth's
surface; major problems of soil erosion; the
contamination of underground aquifers, as well as lakes
and streams; acid rain; and myriad other difficulties.
Agriculture is viewed as a contributor to, as well as a
victim of some of these global environmental difficulties.
Agricultural Sustainability In The United States
As a consequence of many of these
environmental problems, agricultural sustainability has
emerged as a very prominent issue in recent years within
the United States. The focus, however, has not been
nearly so much on meeting global food needs as on
environmental and natural resource issues.
Alternative Agricultural Systems
In recent years, the concept of alternative
agricultural systems has evolved within the United States.
Such a term refers to agricultural systems that are
"alternative" to so-called "conventional" systems.
The U.S. Dept. of Agriculture (USDA) has
defined alternative agriculture as "a production system
which avoids or largely excludes the use of synthetically
compounded fertilizers, pesticides, growth regulators and
livestock feed additives to the maximum extent
feasible...." Increasingly, the term "alternative
agriculture" is being used to include what is commonly
referred to as organic farming, regenerative agriculture,
and low-input agricultural systems. In some circles, these
alternative systems are being equated with sustainable
agriculture. In fact, these terms are often used
interchangeably. For example, Robert Rodale, the late
head of the Rodale Institute of Pennsylvania, suggested
that "sustainable was just a polite word for organic
LISA (Low-Input Sustainable Agriculture)
The term "LISA," advanced by the USDA, has
gained widespread use as a form of alterative agriculture.
Many have stressed, however, that it is inappropriate to
attempt to treat low inputs as synonymous with
sustainability. Using commonly accepted definitions,
sustainable systems may or may not involve lower inputs.
Lower usage of herbicides, for example, may result in
higher inputs of labor. Some have also objected to the
imprecise nature of the term "low inputs." What inputs?
Low in relation to what? How low?
It would appear that the basic concept of
sustainability is being significantly distorted by the term
LISA and by the manner in which alternative systems,
such as organic farming and regenerative agriculture, are
being equated with sustainable agriculture. Such
alternative systems tend to focus primary attention on the
goal of reducing or eliminating the use of chemical
inputs-advocating in their place the use of animal and
green manures, crop rotations, and other related
Many of these practices endorsed by alternative-
agriculture advocates have well-recognized merit.
However, one must question the feasibility or practicality
of generally incorporating many of these practices in U.S.
commercial agricultural operations in ways that can
achieve productivity and profitability objectives.
National Research Council's Report
On Alternative Agriculture
In 1989, the National Research Council (NRC)
of the National Academy of Sciences published what has
become a highly controversial document entitled
"Alternative Agriculture" (National Research Council,
1989). This report strongly espouses the merits of
alternative agricultural approaches in contrast to
conventional systems. Many individuals and groups have
criticized the report, suggesting that it lacks the research
information and background to justify its strong
endorsement of alternative agricultural practices. Dean
Kleckner, president, American Farm Bureau Federation,
suggests that it gives "an inaccurate and too optimistic
view of both the environmental and economic benefits of
alternative agriculture" (Hileman, 1990).
The most comprehensive analysis and
commentary of the NRC report was provided by the
prestigious Council for Agricultural Science and
Technology (CAST). More than 40 scientists provided
commentaries on the report, and in June 1990, CAST
representatives testified before a Joint Committee of
Congress on the subject of alternative agriculture. CAST
and its member scientists were generally complimentary
of the goals of the NRC but highly critical of the
techniques used in the study and the conclusions reached
(Council for Agricultural Science and Technology,
More Balanced And Substantive Approaches
It should be noted that other individuals and
organizations in the United States are approaching
sustainable issues on a much more balanced and
substantive basis by taking into account not only
environmental issues, but also the productivity and
economic viability of such systems.
The American Society of Agronomy, for
example, defines a sustainable agriculture as "one that
over the long term (1) enhances environmental quality
and the resource base on which agriculture depends, (2)
provides for basic human food and fiber needs, (3) is
economically viable and (4) enhances the quality of life
for farmers and society as a whole" (Wail, 1990). I think
this is a very sound characterization of what sustainable
agriculture is all about.
The Research Advisory Committee (RA) of the
U.S. Agency for International Development (USAID)
addressed at some length the issue of low-input and
sustainable agriculture. In response to the contention by
some that modem or conventional agricultural systems
were not sustainable, RA said, "...Many modem
agricultural production systems are not only sustainable,
they have, in fact, created the fertility and resource base
that sustains them. Some of the nation's most productive
soils were once considered infertile and nonproductive....
Most low input systems require high labor input and are
often characterized by low output." Michael Lipton,
International Food Policy Research Institute (IFPRI),
refers to the "dangerous nonsense of believing that one
should strive for low input, high output agriculture"
John Ikerd, Univ. of Missouri, provides further
perspective on this subject, suggesting that "...a
sustainable agriculture must be made up of farming
systems that are capable of maintaining their productivity
and usefulness to society indefinitely.... In the long run,
farming systems must be productive, competitive and
profitable or they cannot be sustained economically.
Also, systems must be ecologically sustainable or they
cannot be profitable in the long run" (Ikerd,1989).
It might be noted that USDA seems to be
modifying its stance with regard to LISA. In a recent
speech, Charles Hess, former USDA Assistant Secretary
for Research and Education, said this about sustainable
agriculture: "Overall, agriculture is endeavoring to
operate in an environmentally responsible fashion, while
continuing to produce both economically and profitably.
Sustainable agriculture is most emphatically not a return
to the low tech' production methods of the 1930s. On the
contrary, it is the use of the very best in technology in a
balanced, well-managed, economically viable, and
environmentally responsible system" (Hess, 1991). To
me, this is an excellent characterization of what
sustainability is all about.
Public Concern About Chemicals
The great emphasis on alternative approaches to
conventional farming methods results, in part, from the
concern of many people about the potential harmful
effects of chemicals. Unquestionably, problems have
arisen from the use and, especially, the misuse of
chemicals. Illnesses and even deaths have been caused
by the use of pesticides, particularly by applicators who
were not using the materials correctly. Certain pesticides
have also caused damage to wildlife species, especially in
earlier years when more persistent forms, such as DDT,
were used. Furthermore, there is evidence that
agricultural chemicals are finding their way into surface
and subsurface water supplies.
How serious this problem may be is still subject
to some conjecture. The fact that there may be minute
quantities of chemicals in water supplies does not
necessarily mean that such levels may pose problems to
Chemicals And Human Health
If agriculture is to be sustainable, it must,
among other things, provide safe and healthy food. There
is growing evidence that the hazards of chemical residues
on food are not nearly as great as some contend.
Sanford Miller, dean, Graduate School of
Biomedical Science, Univ. of Texas Health Science
Center, said, "The risk of pesticide residues to consumers
is effectively zero." In referring to the Delaney
Amendment, which could ban the use of any chemical
that gives a positive test for cancer in rodents no matter
how low the concentration, Miller concluded, "If we
apply Delaney (standards) to all foods, we would never
get to die of cancer we would all starve to death because
we would have to ban all the foods we now eat"
Bruce Ames, professor of biochemistry and
molecular biology, Univ. of California, Berkeley,
suggests that 99.9% of all pesticide carcinogens now
ingested by humans are natural; that is, they are generated
as defense mechanisms within the plants themselves"
(Brookes,1990). He further reports on the level of
natural carcinogens in various foods and says, "You get
more carcinogens in a cup of coffee than in all the
pesticide residues you absorb in a year" (Ames, 1991).
The U.S. Food and Drug Administration also
contends that the risk from natural carcinogens in food is
much greater than that from pesticides, suggesting that
the public is worried about the wrong risk in their diets,
partly because of the exaggerated news accounts of such
scares as Alar in apples, cyanide in grapes, and dioxin in
Dr. Everett Koop, perhaps the most visible and
respected U.S. Surgeon General in history, strongly
opposed the recent "Big Green" initiative in California,
saying that the banning of pesticides under this proposal
would not have positive health effects and emphasizing
that "public policy should be based on science, not on
scare tactics" such as those used by the Big Green
proponents (Brazil, 1990).
Serious harm has been done to agricultural
enterprises by scare tactics such as those claiming that
Alar on apples represented a serious threat to human
health. The assertion by Ed Bradley on the television
show "60 Minutes" that "the most potent cancer-causing
agent in our food supply is a substance (Alar) sprayed on
apples to keep them on the tree longer and make them
look better" (Bradley,1989) proved to be totally
unsubstantiated and, in fact, ludicrous. Yet the Alar
episode cost apple growers an estimated $100 million or
more in lost sales.
There is not much humor in situations like this -
especially for those directly affected. Every now and
then, however, someone comes along to inject a little
humor into such matters and helps keep them in
perspective. Recently, I came across an article by
syndicated newspaper columnist Dave Barry entitled
"Organic Gardening Concept Has Bugs In It"
(Bary,1991). Below are some excerpts from his column:
"Spring is here, and as an educated,
environmentally sensitive nutrition fanatic, you should
definitely think about organically growing your own fruits
and vegetables.What do we mean when we say
'organically grown' fruits and vegetables? Technically,
we mean 'fruits and vegetables with insects living in
them.' Insects are an important source of protein, which
is highly nutritious.
Look at bats. Bats eat a lot of insects, and
they're extremely healthy. They can spend a wild night of
flying around screeching and sucking blood from unwary
victims, yet when they get back to the cave they still have
enough 'zing' left to sneak behind a stalactite for some
hot sonar-enhanced sex...
This is in stark contrast to the average American
consumer, who rarely makes it through the monologue on
'The Tonight Show.' Why? Because the average
American consumer is eating SUPERMARKET fruits
and vegetables, which are known to contain prepare to
be alarmed chemicals.
Of course not all chemicals are bad. Without
chemicals such as hydrogen and oxygen, for example,
there would be no way to make water, a vital ingredient
in beer. But many of the fruits and vegetables that you
buy in supermarkets have been saturated with a class of
chemicals that are defined, technically, as 'chemicals with
long scary names,' such as
chemicals can be harmful. In one laboratory experiment,
they were fed to a group of rats for six months, at the end
of which 68 percent of the rats had become cigarette
Why do fruit and vegetables growers put such
dangerous substances on your food? Actually, there's a
very sensible explanation: They want to kill you. No,
seriously, they use chemicals for many good reasons,
which will be thoroughly discussed about a week from
now in an irate letter to the editor written by the attorney
for the Fruit and Vegetable Growers Association.
Nevertheless, as a modem concerned paranoid
consumer you should definitely grow your own food
organically. We do this in our household. We have a tree
in our yard, planted by the former owner, Bob, who told
us that is was either a lime tree or a grapefruit tree, we
We never put chemicals on it, and every year it
produces a nice crop of organic units the size of either
large limes or small grapefruits with some kind of skin
problem that looks like fruity leprosy. We monitor these
units carefully until the exact moment when they have
ripened to perfection, then we continue to monitor them
as they fall on the ground and are consumed by gnats.
We've done this for two years now and have yet
to notice any serious illness in the gnat community."
Yes, a sense of humor is helpful to puts things
in better perspective.
Despite widespread evidence that the health
hazards of pesticides are often exaggerated, I would
emphasize that it is incumbent on those in agriculture to
do everything possible to reduce and, to the extent
possible, eliminate such potential hazards. As long as the
public perceives there to be a problem, there is, indeed,
a problem. More research is needed with chemical inputs
to determine optimum levels of usage while avoiding
undesirable consequences, if any, from such usage.
Such research can undoubtedly lead to
reductions in the use of some pesticides through various
approaches, including the continuing development of
genetic resistance to many plant diseases and insects.
Research can also help develop more effective biological
approaches to pest control, as well as improve systems of
integrated pest management.
Opportunities to reduce the use of fertilizers are
not as apparent as with pesticides, since agricultural
productivity is often correlated very directly with levels
of fertilizer use. The Food and Agricultural Organization
(FAO) of the United Nations estimates that from 1965 to
1976, approximately 55% of the increase in crop yields
in developing countries could be attributed to fertilizers
(Food and Agricultural Organization, 1981).
Research must continue to determine what
levels of fertilizers should be used to meet the demands
for agricultural products and give the producer adequate
economic return, as well as ensure adequate food
supplies at a reasonable cost to consumers. Where
fertilizers contribute to environmental difficulties, such as
nitrate or phosphate pollution of water sources, research
must be accelerated to develop the means of overcoming
An Antiscience Bias
There seems to be a significant antiscience bias
that characterizes much of the current alternative-
agriculture movement. Such attitudes are truly
unfortunate because the challenge of achieving
sustainable agricultural systems rests, in large measure,
with scientific institutions. Science is not the problem.
Indeed, science offers the key to achieving
sustainable systems. Traditional agricultural systems
were sustained indefinitely until greater demands were
placed on such systems by increasing population
pressures. Research is essential to develop the
technology needed to sustain these systems at levels
above their natural steady state.
Research must focus increased attention on
developing and applying the technology needed to
achieve both the economic and ecological dimensions of
sustainability. The planet Earth cannot achieve a
sustainable agriculture and meet the ever-growing needs
of people without the use of modem technology,
including the appropriate usage of agricultural chemicals.
Humanity In Harmony With The Environment
A long-time friend and colleague, Orville
Freeman, former U.S. Secretary of Agriculture, recently
sent me a copy of a speech he had given at the World
Future Society Conference dealing with the future of the
biosphere. In his paper, "Humanity vs. Environment,"
Freeman addressed the basic dilemma of protecting our
planet's environment while feeding its rapidly growing
hungry population (Freeman, 1989). He referred to those
who oppose the use of modem technology to improve
food production for fear of contributing to environmental
problems and responded to such arguments by
emphasizing that humanity's need for food will not be met
without the use of modem technology. I agree fully with
such as assessment. And I would add that science and
technology can and must help deal with those problems
that might grow out of the use of such technology.
The issue is not one of humanity vs. the
environment This suggests some irreconcilable conflict
that I do not believe exists. Perhaps a more appropriate
title would be "Humanity in Harmony with the
Environment." This is what we must strive to achieve -
helping agriculture and, indeed, all of humanity to
become truly in harmony with the environment.
The agricultural science professions have a
great challenge to contribute to such an objective. I
commend you for what you have already done in this area
and wish you well in future efforts.
It is a great pleasure to be with you.
Ames, B. 1991. Lecture, Univ. of Florida, 5 June 1991.
Anonymous. 1987. Food 2000: Global policies for
sustainable agriculture. Zed Books, London.
Anonymous. 1989. LISA: New concept or just a new
name. Progressive Farmer, Oct. 1989.
Barry, D. 1991. Organic gardening concept has some
bugs in it. Gainesville Sun, 17 Mar. 1991,
Bidinotto, R.J. 1990. The great apple scare. Readers
Digest, Oct. 1990, pp.53-58.
Bradley, E. 1989. 60-Minutes. CBS-TV, 26 Feb. 1989.
Brazil, E. 1990. Another salvo at "Big Green." San
Francisco Examiner, 26 Oct. 1990.
Brookes, W.T. 1990. The wasteful pursuit of zero risk.
Forbes, 30 Apr. 1990, pp. 161-172.
Brown, L.A. 1988. Worldwatch paper 85: The changing
world food prospect: The nineties and beyond.
Worldwatch International, Washington, DC.
Council for Agricultural Science and Technology. 1990.
Alternative agriculture-Scientists' review, July
1990. Council for Agricultural Science and
Technology, Ames, IA.
Food and Agricultural Organization. 1981. Agriculture:
Towards 2000. Food and Agricultural
Organization of the United Nations, Rome.
Food 2000: Global policies for sustainable agriculture.
1987. Zed Books, London.
Freeman, O.L. 1989. The future of the biosphere-
Humanity vs. the environment. World Future
Society Conf., Washington, DC.
Herdt, R. 1988. Increasing crop yields in developing
countries. 1988 Amer. Agr. Econ. Assn. Mtg.
The Rockefeller Foundation, New York.
Hess, C.E. 1991. Importance of ag research to U.S. and
the world. Remarks at Auburn Univ., 4 Apr.
Hileman, B. 1990. Alternative agriculture. Chem. Eng.
News, Mar. 1990, p.5.
Ikerd, J.E. 1989. Sustainable agriculture. Annual Outlook
Conf., 29 Nov. 1989. U.S. Dept. Agric.,
Lipton, M. 1989. New strategic and successful examples
for sustainable development in the Third World.
International Policy Research Inst, Washington,
National Research Council, 1989. Alternative agriculture.
National Academy of Science, National
Academy Press, Washington, DC.
Scheuplein, R.J. 1989. U.S. Food and Drug
Administration, Washington, D.C.
Wail, R.R. 1990. Defining and using the concept of
sustainable agriculture. J. Agron. Educ. 19:126-
World Commission on Envirnoment and Development
1987. Our common future. Report of the
World Commission on Environment and
Development. Oxford Press, New York.
Recycling Urban and Agricultural Organics in Fields and Forests
*Wayne H. Smith and Aziz Shiralipour
About 750 million dry metric tons of
biodegradable organic wastes are produced annually in
the US. The 1995, official Florida population was more
than 13.8 million and the total amount of municipal solid
waste produced annually grew to about 24.3 million tons
(Anon., 1996). This translates into 9.6 lb/person/d or 1.7
ton/person/yr. On a per capital basis, Floridians generate
twice the national average. The total organic stream
includes materials produced by livestock, crop residues,
biosolids, food processing, logging, and wood
manufacturing, other industries, and municipal refuse.
The current method for processing of organic residues
leads to environmental problems and is not sustainable.
However, there is a growing recognition and appreciation
of the need for and the benefits resulting from effective
management of biodegradable organic materials, to the
point that such materials are often regarded as resources.
Because of this, alternative methods of organic material
recycling and processing which promote conversion to
useful products are being advocated. Cost-effective
integrated organic resources management to provide soil
amendments and other useful products linked to a system
to redirect the products to beneficial uses would lead to
sustainable ecosystems and solve the environmental and
economic problems facing society.
Organic materials represent a significant
quantity of feedstocks for conversion to compost,
stabilized residues that can improve soil physical and
chemical conditions. Utilization of organic material is of
utmost importance in maintaining the tilth, fertility, and
productivity of agricultural soils, protecting them from
water and wind erosion, and preventing nutrient losses
through runoff and leaching. Organic materials can also
increase soil water-holding capacity, water infiltration,
aeration and permeability, aggregation and rooting depth;
decrease soil crusting and bulk density; keep soil
organisms balanced; and reduce soil pathogens
(Shiralipour et al., 1992).
Several ongoing projects coordinated by the
UF/IFAS Center for Biomass Programs are designed to
W.H. Smith and Aziz Shiralipour. Center for Biomass
Programs, University of Florida, Gainesville, FL.
Manuscript received 31 March 1997. Corresponding
demonstrate the benefits and safe use of compost
applications in various uses. There are two
comprehensive statewide projects and several others that
target specific uses. The two active comprehensive
projects build upon an earlier large project addressing
water conservation benefits (Smith, 1994; 1995).
A MARKET DEVELOPMENT PROGRAM
FOR COMPOSTS IN FLORIDA
Demonstration of Safe Use of Compost
To remove barriers to compost acceptance, a set
of projects was designed to: 1) demonstrate the biological
and chemical remediation of pesticides during
composting, and 2) compost maturity/stability measures
important to N and toxic metal availability and
accumulation in crop parts.
Demonstrate the biological and chemical
remediation of pesticides during composting
Black Kow' manure compost and composts
from various facilities in Florida were used for pesticide
assays. A quality assurance (QA), quality control (QC)
testing protocol was established for pesticide (endrin,
lindane, methoxychlor, toxaphene) and herbicide (2,4-D,
silvex) detection in compost. Samples tested thus far
have confirmed the hypothesis that pesticides are not
present in mature/stable composts. This is either from
not being present to begin with or from remediation of the
chemicals through the composting operation. Air-tight
composters have been designed to study the
bioremediation when composts are "spiked" with known
quantities of a pesticide. Radio-labeled atrazine is the
model herbicide being used.
Compost maturity/stablity measures important to N
and toxic metal availability and accumulation in crop
Several methodologies were utilized to
measure the maturity/stability of the compost products.
These methods include total C/N ratio, water-extractable
organic C and N and also its ratio, optical density of the
water-extract, and respiratory study based on CO,
evolution. The most reliable and clear indicator for
compost maturity/stability was determined to be
respiratory release of CO,.
Although the total nutrient and heavy metal
quantity varied in different composts, in all cases, the
levels were far lower than the limits established by
Department of Environmental Protection (DEP)
regulations. Water-extractable metals were low,
verifying that the bioavailability of metals from these
materials do not pose risks.
Demonstration of Compost Benefits
A set of projects was designed to demonstrate
the benefits of compost applications to: 1) sandy soils
used for vegetable crop production, 2) landscape beds to
enhance establishment of woody ornamentals, and 3)
turfgrass soils to determine effect on N release and on
leaching of nutrients and organic compounds.
Several compost types were utilized in these
projects. These included urban plant debris (yard waste)
compost obtained from Enviro-Comp Facility
(Jacksonville, FL), biosolids composted with UPD from
Palm Beach Solid Waste Authority Facility (Palm Beach,
FL), municipal solid waste (MSW) composted with
biosolids from Bedminster Facility (Sevierville, TN), and
MSW compost from Sumter County, FL.
Benefits of compost applications to sandy soils used
for vegetable production
This project was initiated to build upon the base
knowledge obtained in 1992 and 1993. Compost was
applied to tomatoes (Lycopersicon esculentum) planted
in rotation with watermelons (Citrullus lanatus) and
tomatoes in rotation with bell peppers (Capsicum
annuum). The results indicated that: a) immature
compost delayed tomato plant growth due to N-rob; b)
when tomatoes were planted in rotation following
peppers grown in compost treated soil, yield of tomatoes
was 30% greater than yield without compost treatment;
c) watermelons planted in rotation following tomatoes
produced 30% to 50 % yield increase compared to soil
with no compost treatment; and d) compost increased soil
organic matter concentration, water-holding capacity, soil
mineral concentrations, and pH in proportion to rate.
The objectives of the subsequent project were
to determine the optimum scheduling of compost
applications for improvement of soil physical properties
important to transplant health, stand establishment, crop
yield, and crop quality. Although the bell pepper and
tomato plants grew well in both compost-amended and
unamended plots, benefits were obtained in terms of
increased yield and fruit quality. Extra-large tomato yield
was significantly greater where Enviro-Comp compost
was applied compared to unamended soil. Marketable
yield in 25-lb cartons/a was 1158 for Enviro-Comp in
comparison to 939 for the unamended soil. The
unamended treatment produced the largest yield of
medium tomatoes (410 cartons in comparison to 325,
370, and 337 cartons for Bedminster, Palm Beach
County, and Enviro-Comp, respectively), had the highest
percentage of fruit with "yellow shoulder" (28% in
comparison to 9%, 16%, and 7% for Bedminster, Palm
Beach County, and Enviro-Comp, respectively), and
produced the firmest tomatoes. Tomatoes from the
Bedminster compost treatment took 1 to 1.5 d longer to
naturally turn from green to red at room temperature
(15.1 d in comparison to 13.5, 13.3, and 14.1 d for Palm
Beach County, Enviro-Comp, and unamended treatment).
There were no statistically significant differences among
tomatoes for plant dry weight (195 g, 175 g, 165 g, and
174 g per plant for Bedminster, Palm Beach County,
Enviro-Comp, and unamended treatment, respectively) or
any of the other yield or quality variables measured
(percent of fruit rots, fruit scars, fruit puncture, fruit
cracks, fruit zipper, and fruit shrivel).
'Fancy' bell pepper yield was greatest in the
Bedminster compost treatment compared to the other
treatments (397 cartons compared to 323, 335, and 349
for Bedminster, Balm Beach County, and unamended
treatments, respectively). There was no differences in
total pepper yield between the treatments (1335, 1325,
1340, and 1254 cartons for Bedminster, Palm Beach,
Enviro-Comp, and untreated, respectively). The Enviro-
Comp treatment produced the firmest peppers, and the
unamended treatment produced the softest. There was no
difference between treatments in terms of fruit color or
post-harvest variables measured. Benefits were also
evident with the spring watermelon crop ( in the ground
at the time of the reporting).
The soil water characteristic curve was
determined for unamended sandy soil that was amended
with the high rate of Bedminster (80 ton/a), Palm Beach
County (27 ton/a), and Enviro-Comp (80 ton/a)
composts. Soils used for the measurement of water-
holding capacity were sampled from plots immediately
after tomato and bell pepper seedlings were transplanted,
which was 2 to 4 mo. after compost incorporation. Only
the Enviro-Comp treatment showed slightly higher water-
holding capacity than unamended soil.
Compost applied to landscape beds to enhance
establishment of woody ornamentals
In earlier experiments, woody plants were
grown in pots with media mixes. In the potting media,
composted materials from various facilities were
evaluated in treatments ranging from 100% compost to
100% replacement of just the peat portion of the
container media. Biomass data were compiled for some
woody ornamentals grown in containers with composts
and compared to a control commercial mix. Biomass
production in stand-alone composts was greater than in
the control medium in many cases. Other compost
treatments produced biomass levels similar or better than
As a follow up, this project is determining if
composts incorporated in landscape soils hastens
establishment of container grown woody shrubs and the
causes for the improved root growth and other biological
measures associated with the compost application. Three
types of composts (Bedminster, Palm Beach County, and
Enviro-Comp) were applied at 1, 2, 3, and 4 in layers.
Two irrigation regimes were applied: heavy irrigation
(daily for the first 2 mo, every other day for the 3rd and
4th mo, and twice a wk afterwards) and light irrigation
(every other day for the first 2 mo, twice a wk for the 3rd
and 4th mo and once a wk afterwards). Compost
treatments had no significant effect on estimated root
mass for ligustrum (Ligustrum sp.). However, the control
and the lowest levels of compost amendments had the
greatest root mass for viburnum (Viburnum sp).
Irrigation regime appears to have little effect on root
growth of any species. Soil treatments, however, are
having significant effects on root growth. Analysis of
data suggests that canopy effects are opposite to those
measured in the roots. Plants grown in highest levels of
compost appear to have larger canopies and higher levels
of tissue N. High N levels in the tissue my explain what
appears to be lower root:shoot ratios. All compost
amendments appear to have completely substituted for
fertilization requirements. The optimum soil treatment to
date appears to be 2 in of the Palm Beach County
Effect of compost in turfgrass soils on N release and
on leaching of nutrients
Earlier tests indicated that a rate of 30 to 70%
compost to sandy soil in pots was optimum for growth
and quality of turfgrass (St. Augustinegrass)
(Stenotaphrum secundatum). A municipal solid waste
compost was incorporated into a fine sandy soil.
Compost incorporation consistently increased the quality
of St. Augustinegrass. Clipping weights generally were
greater from compost amended plots. During dry
periods, the established turfgrass did not wilt as quickly,
thus reducing the frequency of irrigation.
Although composts contained nutrients in
addition to those from fertilizer, nutrients in the leaching
water were reduced. In compost treated soil, pesticides
were not detected in water leached from the soil.
Compost treatments up to 30% resulted in improved
nutrient retention (less leaching). This project is
determining the rate ofN mineralization in three compost
(yard trimmings, biosolids, MSW) and identifying
laboratory indices related to the mineralization.
Field, greenhouse, and laboratory studies were
conducted subsequently to evaluate N release from three
compost sources. The Palm Beach Solid Waste
Authority biosolid compost had the highest content of N,
and the Enviro-Comp had both the lowest content of N
and the highest C/N ratio. Based on available
mineralization data from the first year, Palm Beach
compost released the greatest amount of N and the
Enviro-Comp source the least. No volatile or semi-
volatile organic were found in CaC1, extracts from
Evaluation of Composted Materialsto be Utilized
in Florida Road and Median Plantings
Under a grant awarded by the Florida
Department of Transportation, the University of Florida's
Department of Environmental Horticulture and the Soil
and Water Science Department are conducting both field
and greenhouse studies to evaluate and recommend
specifications for compost as a soil amendment in
roadside plantings. The 3-yr project will examine
germination, growth, and establishment of utility turf in
soil amended at three different rates with three types of
commonly available, commercially produced compost
and will evaluate turf response to the nutritional value of
manure and biosolid-based composts applied as top
The three types of compost utilized in the study
are: 1) a straight yard waste compost provided by
Enviro-Comp in Jacksonville and AmeriGro in south
Florida, 2) a yard waste with biosolids compost provided
by the Palm Beach County Solid Waste Authority, and 3)
a municipal solid waste with biosolids compost provided
by the Bedminster facility in Sevierville, TN. Because
the study seeks to establish the high-end loading tolerance
for the often poor and severely disturbed soils found
along newly constructed roads, compost application rates
in the field were 100, 200, and 300 dry metric ton/ha.
The compost is tilled into existing soil to a depth of 15 to
20 cm. The field study portion of the project is being
conducted at sites in south, central and north Florida
(Broward, Hernando, and Taylor counties, respectively).
Two greenhouse studies have been completed,
and a third is under way in the University of Florida
Envirotron in Gainesville. These tests use three soil types
(< 1% organic matter, > 1% organic matter, and sand)
and three rates of incorporation (15%, 30% and 60%) for
each of the composts. The amended soils and the controls
are seeded with an 80:20 mix of bahiagrass(Paspalum
notatum) /bermudagrass (Cynodon dactylon). In addition
to evaluating rates of germination, establishment, and
yields, the investigators are collecting and analyzing pot
Preliminary plans for a field study evaluating
several types of compost as top dressing for existing
stands of grass have been developed and a site selected.
Also, included in the project is a literature search, which
has been conducted, as well as a telephone survey of
Departments of Transportation in selected states
regarding their specifications for and utilization of
compost. Telephone interviews have also been
conducted with various government and private
environmental and waste management agencies as well as
with academic researchers at this and other institutions.
The standards specified by the University of Florida team
must go through the approval process and be finalized by
the Florida Department of Transportation (DOT) before
production of the educational materials for use with
training DOT personnel.
Below are some projects supported by the
Center to position faculty to be competitive for extra-
mural funding and/or solve short-term problems:
Impact of Compost on Plant Growth and Irrigation
Composted municipal solid wastes (MSW) from
the Sumter County Solid Waste Facility were applied at
the Alachua County Extension Office. The material was
spread on the plot in a 4-in-thick layer (approximately
200 ton/a) and was rototilled to a depth of approximately
5 to 6 in.
Both areas, with and without the compost, were
planted with identical landscape plants. For the large
background plants, fetterbush (Lyonia lucida), radish
palm (fam. Palmae), and needle palm (Rhapidophyllum
hysterix) were selected. For medium size filler, dwarf
nandina (Nandina domestic) and in the front, liriope
(Liriope muscan) 'Evergreen Giant' were planted. After
planting, the lateral lines of the irrigation system were
installed and the area was mulched with pine straw. The
addition of composted material resulted in significant
water use reduction. The soil water potential remained
higher for the longer time and the irrigation system did
not operate as frequently. During the test period, the total
water savings in the compost treated area were 12%
compared to the untreated area
Municipal Solid Waste Compost Application to
Municipal solid wastes (MSW) compost from
Sumter County was applied and disked in at either 26, 52,
or 104 dry tons/a (dt/a). For comparison, yard waste
composts from three sources were applied and disked in
at either 9,18, or 36 dt/a, and combined kitchen and yard
waste compost was applied and disked in at either 4, 8, or
16 dt/a These plots were compared to plots treated with
0, 150,300, or 600 lb. N/a as ammonium nitrate. Annual
ryegrass was grown and harvested monthly. Without
irrigation, a good stand of ryegrass was achieved on plots
treated with MSW compost. The rate of application that
appeared to give the best growth was 52 dt/a for the
MSW compost. The kitchen and yard waste combined
compost applied at 8 dt/a resulted in the highest yields for
that type of compost. All of the yard waste compost
applications resulted in spotty germination and relatively
reduced yield. It is expected this may be due to N
immobilization or physical impedient of germination or
reduced water infiltration.
Grass Forage Production Following Land
Application of Urban Plant Debris.
Plots were set up in a Gilchrist County field
where 200 ton/a of urban plant debris (UPD) had been
incorporated into the soil without any processing 3 or 9
mo prior to planting. Nitrogen fertilizer was added at 0,
100, and 200 lb/a. Where UPD had been applied 9 mo
before planting: sorghum-sudangrass (Sorghum bicolor
x S. sudanense) showed no N deficiency, produced just
as much without N fertilizer as with N fertilizer, and
averaged 21 tons of fresh forage (2.5 tons of dry
weight)/a. Where UPD had been applied 3 mo before
planting: sorghum-sudangrass growth was stunted
without N fertilizer, yield was considerably less than
where UPD had been incorporated for 9 mo, either 100
or 200 lb fertilizer N/a produced an average of 13 tons of
fresh forage /a (1.4 tons of dry weight/a), and yield
without fertilizer Nwas 7.3 tons of fresh forage/a (0.8 ton
Compost Application in Forests
Growth and elemental content of slash pine (Pinus
elliottU) 16 yr after treatment with garbage
composted with sewage sludge.
This study has assessed tree growth and
elemental tissue concentrations in a slash pine In
plantation treated 16 yr previously with four rates (0,
112, 224, and 448 metric ton/ha) of municipal solid
waste (MSW) composted with sewage sludge. Tree
growth was significantly greater where MSW compost
was applied. Stem wood biomass increased from 55.7 to
94.7 metric ton/ha, a 1.7-fold increase over the control
for the heaviest compost application rate. Annual tree
basal area increment responses were also largest and
most long-lasting (up to 9 yr) for the 448 metric ton/ha
rate. Significant but modest treatment-associated
increases in concentrations of N, P, B, Fe, Al, and Zn in
pine tissues (foliage, stem wood), and of P and Ca in
Rubus spp., a dominant understory plant, were found
after 16 yr. Analysis of pine xylem tissues corresponding
to the juvenile and post-crown closure growth phases
revealed significantly higher concentrations of K, Ca, Mg,
Cu, Al, and Zn in the later period. Results suggest that
land spreading and recycling degradable organic wastes
in forests can increase tree and understory growth without
long-term deleterious ecosystem effects.
Compost test demonstration in slash pine forested
In 1970, an experiment using composted
garbage was installed that doubled slash pine growth
where composts were applied. Subsequently another
pine research project was installed to demonstrate the
benefits of composted MSW for tree growth and to
observe the resulting physical and chemical changes.
Composted MSW was applied on 15x30 m plots, at
levels of approximately 100, 200, and 300 dry metric
ton/ha, at two different flatwoods sites. At one site
(seedling site), compost was applied and incorporated
into a sandy bare soil and slash pine seedlings were
subsequently planted. At the other site (forest site), the
compost was top dressed between the rows of a 6.5-yr-
old slash pine plantation. Weed competition at the
seedling site was severe, and by the second yr after
planting, <5% of the seedlings had survived. Tree
growth increased about 50% with the two higher
application rates at the forest site. Soil water content
increased at the seedling site where the compost was
incorporated, but decreased at the forest site where the
compost was top dressed.
The research projects presented here are
addressing several important compost parameters and
utilization opportunities. These projects revealed that
application of compost pose no serious threats and if
mature, composts are safe and can result in benefits to
The projects presented here are completed or
are ongoing by the following IFAS researchers: R.C.
Beeson, G.H. Brinen, J.L. Cisar, S.R. Colbert, G.
Fitzpatrick, R.N. Gallaher, D. Graetz, D. Haman, E.J.
Jokela, G. Kidder, L. Korhnak, M. Marshall, T. Obreza,
D. O'Keefe, J. Rechcigl, H. Riekerk, G.H. Snyder, A.
Shiralipour, W.H. Smith, N.P. Thompson, C.S. Vavrina,
M. Weaver, C.I. Wei, W.B. Wheeler.
Anonymous. 1996. Solid Waste Management in Florida.
Department of Environmental Protection.
Shiralipour, A., D. B. McConnell, and W.H. Smith. 1992.
Uses and benefits ofMSW compost: A review
and an assessment. Biomass and Bioenergy
Smith, W.H. 1994. Recycling Composted Organic
Materials in Florida. BP-2. Univ. of Florida,
Inst. of Food and Agr. Sci., Gainesville, FL.
Smith, W.H. 1995. Composting in the Carolinas. Proc.
of a Conference on Composting Solid
Waste, Yard Waste and/or Biosolids. Charlotte,
Use of Animal Manure in Production of Wholesome Food
*H. H. Van Horn and P. W. Joyce
Nutrients in manure are recyclable.
Applications of manure nutrients to plants that benefit
from nutrient fertilization is the most used method to
recycle. To avoid excessive applications of
environmentally sensitive nutrients at inappropriate
points, it is helpful to budget nutrient flow through the
total animal-producing farm system (e.g., Van Horn et al.,
1991; 1996). Critical elements to develop a whole-farm
nutrient budget to balance nutrient use in the environment
include: 1) nutrients excreted by food animals, 2)
potential nutrient removal by plants, 3) losses of nutrients
within the manure management system and in fertility
management for crop production, 4) combining steps 1 to
3 to assess whole-farm nutrient status, and 5) alternatives
that permit export of nutrients off-farm, if necessary.
NUTRIENTS EXCRETED BY FARM ANIMALS
It has been demonstrated previously (Morse et
al., 1992; Van Horn et al., 1994; 1996; Tomlinson et al.,
1996) that original nutrient excretions are easily
estimated by simple animal input-output comparisons.
Thus, farmers are encouraged to use information from
their feeding program to predict nutrient excretion.
Accurate nutrient intake is the most important single
source of information needed to estimate original nutrient
excretions. Nutrition managers of large animal-food
production units, who have access to computerized
records of feed nutrient deliveries to animals, are key
consultants in developing nutrient budgets. Records of
food production sales off-farm along with measured or
estimated nutrient content of the products provide the
output component needed to accurately estimate manure
nutrient excretions. Nutritionists also are skilled in
balancing nutrients in diets so that animal nutrient
requirements (e.g., Anon., 1984; 1989) can be met with
as little excess of environmentally sensitive nutrients as
Eliminating dietary excesses where they exist is
the first step to reduce on-farm nutrient surpluses. It is
well documented that many, perhaps most, dairy and beef
'H.. Van Home and 2P.W. Joyce. 'Department of Dairy
and Poultry Sciences and2 Duval County Extension,
IFAS, University of Florida, Gainesville, FL. Manuscript
received 21 March 1997. Corresponding author.
cattle producers overfeed P; for example, dairymen often
feed 0.50 to 0.60% P when NRC (Anon., 1989)
recommends an average of about 0.42% for lactating
cows. Reducing P to NRC (Anon., 1989)
recommendations would reduce P excretion per cow by
at least 20 lb/yr (Van Horn et al., 1996). The principles
are the same for all animal species, i.e., reduce intake of
environmentally sensitive nutrients to the fullest extent
possible because excretions will be reduced to an even
greater extent than intake.
NUTRIENT REMOVALS BY PLANTS
AND AGRONOMIC ALLOWANCES
One generally acceptable philosophy of land
application of manure is that nutrients can be applied
slightly above the amounts removed by the crops
harvested. A key question is, how much above the
amounts of nutrients removed should be applied and what
factors influence this? Nutrient removals by crops are
easily calculated if we know dry matter (DM) removals
and nutrient compositions on a DM basis. Table 1
illustrates the importance of N, P, and K concentrations
on nutrient removals. Luxury consumption of nutrients
(or increased concentrations in response to fertilization in
the absence of a yield increase) have significant
implications for nutrient budgeting even though potential
for luxury consumption of P seems to be less than the
potential with N and K. The surest method for increasing
P removal seems to be to increase crop yield by avoiding
moisture stress and deficiencies of other nutrients.
Total nutrient removals with multiple-cropping
are illustrated by a long-term research project at Tifton,
Georgia, which was designed to identify a maximum,
environmentally safe application rate of manure nutrients
with a triple-cropping system (Newton et al., 1995).
Flushed dairy manure nutrients were applied through
center-pivot irrigation. The cropping system included
'Tifton 44' bermudagrass (Cynodon dactylon L.) into
which corn (Zea mays L.) was sod-planted for silage in
spring and 'Abruzzi' rye (Secale cereale L.) was sod-
seeded in fall. Harvests included rye for grazing from
about-1 December until 15 February, rye for silage about
20 March (corn planted the day following), corn for
silage in mid-July, low-quality bermudagrass hay about
10 d later, and high quality bermudagrass hay or grazing
until rye was planted again about 1 November. Although
this is an example of one best-case scenario for nutrient
removals, the Georgia data showed that harvests of 510
lb N and 90 lb P/a or more were achieved with
application rates that were environmentally acceptable
(Figure 1). These N and P removals were in a forage
DM harvest of 12.9 ton/a annually which, for the example
budget represented in Figure 1, was fed to 4.2 cows
supplemented with purchased feeds to meet NRC protein
requirements based on ruminally undegradable protein to
minimize dietary N. The manure N was applied as
fertilizer as quickly as possible to minimize N
volatilization losses. Similar crop N removal rates have
been reported for other environmentally acceptable
manure utilization/forage crop systems, and even higher
nutrient removals may be possible with an alternate
system using two crops of corn silage per year plus
winter rye or triple-crop sod-based systems utilizing
Surface runoff and loss to groundwater are
usually within acceptable limits but management
practices must control these losses so that violations of
state water quality standards do not occur. In Figure 1,
values for budgeting of about 20 lb N/a passing to
groundwater and 30 Ib/a to surface water were assumed
to be environmentally acceptable.
The budget illustrated in Figure 1 is based on N.
Thus, it assumes that in this location there is no
environmental risk for surface runoff of P, which was
applied in excess, or to allowing P to accumulate in the
soil. Note also in this budget that manure N recovered as
fertilizer was 646 lb or 70% of excretion (646/923). We
think this is about the best possible recovery of manure N
for fertilizer. If a P budget had been used, only manure
from 2.3 cows could have been utilized in producing
those crops which had a total removal of 90 lb P/acre
(Van Horn et al., 1996). Thus, an appreciable amount of
commercial fertilizer N would have been required to
supplement manure nutrients and achieve proper balance
for fertilizer N and P.
Denitrification is a bacterial process which
converts nitrate in solution to N gas. It is dependent upon
a bacterial energy source, usually in the form of soluble
organic matter, and progresses most rapidly under high
moisture and/or low oxygen soil conditions. For
irrigated, highly diluted manure (less than 100 to 150
ppm N) the loss of ammonia during irrigation is often
proportional to the evaporation loss of water.
Denitrification losses are harder to estimate on the farm
but can be large. Measured denitrification losses have
been found to be in excess of 120 lb/a during some years
when manure application rates were similar to that shown
in Figure 1.
It is important to differentiate between excretion
and recovery. The difference has both environmental and
economic implications. After excretion, manure may be
stored wet, stored after being allowed to dry, flushed with
water to a lagoon or holding pond, spread fresh on land,
or spread in some other form at a later time. The N in
urine, which may be about half of total manure N, is
easily lost to the atmosphere as ammonia because it is
excreted in the form of urea, or in poultry, as uric acid.
Urease enzyme of bacterial origin is present almost
everywhere, so N voided as urea is converted readily to
gaseous ammonia (NH3). The most important practical
factors controlling ammonia volatilization losses are
ammonia concentration (slower for dilute solutions) and
surface area. Other important factors are temperature,
pH (acid conditions reduce volatilization by converting
NH,, a gas, to NH,, which is not volatile), and air
movement If voided on a paved surface in warm weather
and only moderate air movement, essentially all of the
urinary N will be lost unless the area is flushed frequently
or the urine is diluted with water from cow cooling
sprinklers or other sources. Most of the fecal N is in
organic compounds and thus, is much more stable than
A key measure needed on-farm to help evaluate
manure management systems is the amount of N and P
recovered and recycled relative to the amount excreted.
Also, nutrient quantities are needed in order to know the
dollar value realized when crops are fertilized with
manure. Weighing enough loads of manure hauled to the
fields to estimate amount and analyzing enough samples
to predict N, P, and K composition are necessary.
Nutrient recoveries are obtained by multiplying
concentrations by load weights and number. If an
irrigation system is used to distribute wastewater from a
lagoon or holding pond, wastewater analyses are needed
to go with the volume of wastewater distributed. Volume
meters on irrigation pumps are important; if not available,
gallons pumped must be estimated by hours pumped and
estimated gallons/min from pump specifications. Some
suggested estimates for preliminary budgeting if amounts
recovered and compositions have not been measured are:
With quick application and incorporation, for example
irrigation of flushed manure within 5 days after
excretion to crops grown under sprayfield, N
Application of wastewaters from anaerobic lagoon with
a 21-da or longer holding time, N recovery: 20
An average recovery for N in most manure handling
For P, estimate recovery of 90% or more unless an
anaerobic lagoon is used and a discount applied
for what likely remains in the sludge in bottom
of the lagoon. That amount could be as much as
50% in lagoons with 21-da or more average
hydraulic retention time.
For K, estimate recovery of 80 to 90%.
Many underestimate N volatilization losses from
manure and manure-containing wastewaters utilized for
irrigation and fertilizer (e.g.,Gallaher et al., 1995). When
this occurs, crops are undernourished and nutrient
removals are limited by N deficiency, P is overapplied
and accumulates because P removals are less than
WHOLE-FARM NUTRIENT STATUS:
Figure 1 represents a specific nutrient (N)
budget In this case, the cropping system was chosen first
and a cow density selected which achieved balance based
on assumed N losses. In most cases, budgets are
developed with animal numbers and animal production
fixed and calculations are made to estimate nutrients that
need to be utilized for crop production and the cropping
system that can utilize them.
For example, let's assume an animal-producing
farm recovers 24,000 Ib N in manure per yr, 7,000 Ib
actual P per yr, and 14,000 lb K. Recoveries in
approximately these proportions are common. Let's
assume the triple-cropping program represented in Figure
1 is utilized, which removed 510 Ib N/a annually in
harvested crops. Application would have to be somewhat
greater than removals to allow for environmentally
acceptable losses to volatilization of N after a field
application, to denitrification, to groundwater, and to
surface runoff. In Figure 1, the allowance for N was
150% of removal if we calculate application as what went
to the field in irrigated wastewater, i.e., 760 lb N applied
versus 510 lb N recovered in crops harvested. With this
scenario, it would take 27.6 a to utilize available manure
N (21,000 lb N divided by 760 lb N applied/a). For
comparison, let's assume recommended applications for
P and K are 110% of crop removals. The Tifton, Georgia
triple-cropping experiments (Newton et al., 1995; Van
Horn et al., 1996) removed 90 lb P and 425 lb K/a.
Thus, agronomic application rates would be 90 x 1.1 =
99 lb/a for P and 425 x 1.1 = 468 Ib/a for K. The 7000
lb manure P would require 70 a of triple-crop production
and the 14,000 lb manure K would require 30 a. This
example, like almost all manure examples, shows the
manure is P-rich relative to N, e.g., more than twice as
much crop production was needed to utilize P than N. If
soils can be permitted to build up P storage, it may not be
a problem in the short-run to apply manure based on N
content and permit P to accumulate in the soil. In the
long run, however, it is expected that over-application of
P will be discouraged and perhaps prohibited. The value
of the fertilizer nutrients recovered is greater when
manure nutrients are applied utilizing a P budget as well
(Henry et al., 1995). Usually K budgets require acreage
intermediate to N and P budgets.
ALTERNATIVES THAT PERMIT EXPORT
OF NUTRIENTS OFF-FARM
Often, food-animal producing farms do not
produce sufficient crops to utilize nutrients on-farm. This
will be true for most farms ifP budgeting is required to
avoid pollution and utilized to capture the economic value
of manure. WithP budgeting, many more farms will need
to find ways to export manure nutrients for use as
fertilizer on other farms.
Manure Application on Nearby Farms
Large food-animal producing units vary greatly in land
resources that are available on the same farm to produce
crops that will consume the manure nutrients produced.
For example, most dairy farmers have sufficient forage
needs so that traditionally they have maintained a sizeable
farming operation in conjunction with the dairy. Thus,
most dairies, but not all, can recycle their fertilizer
nutrients on-farm if they increase sufficiently the intensity
of crop production on the land they have. Large beef
cattle feedlots and poultry producers, however, almost
assuredly will need to export manure nutrients. Based on
excretion estimates of about 100 lb N/steer-yr, a feedlot
of 50,000 head with 80% occupancy will generate about
4,000,000 lb N/yr. If 50% of the N is utilized effectively
as fertilizer (50% volatilized) for crops requiring 400 lb
N/a, about 5000 a cropland is needed for utilization of the
N. If the feedlot is in a dry area, irrigated cropland will
be required or application rates reduced accordingly to
match productivity of the dry land. One significant
advantage of locating large feedlots in dry regions is that
the manure can be scraped and hauled off-site very easily,
as compared with feedlots located in wet regions.
Earthen structures to contain runoff are very modest in
size compared to high-rainfall areas.
Some regions that do not have sufficient crop production
near the animal production unit have needed to find other
means to utilize or transport manure nutrients off-farm.
Burning manure is a possibility. The first large-scale
resource recovery project in the world to burn cattle
manure as fuel to generate electricity was in the Imperial
Valley of southern California. It was designed to utilize
manure from the many beef cattle feedlots in the valley.
Utilization of poultry litter for fuel is expected to
approach 80% of the litter produced in the United
Kingdom within 5 to 10 yr. When manure is burned, the
ash nutrients still need to be managed accountable.
A significant amount of dried manure, composted
manure, or a combination of dried and composted manure
is bagged and sold as organic fertilizer. An example with
dairy manure is a dairy cooperative in the Chino Valley
in California which was set up to move manure off of
large, intensive drylot dairies located in an urban area.
Firms exist in the Southeast also that market manure-
Composting is a logical way to process wetter
manures (but not slurries) when livestock producers must
create a product that must move off-farm and be stable
enough when suburban users or agricultural users near
urban centers want to utilize it. Composting is relatively
costly, labor intensive, and some of the most valuable
fertilizer constituent, N, is driven off to the atmosphere
during processing. Therefore, dairies and feedlots usually
consider the process only if a marketable product is
created that will help them remove the excess nutrients
from the farm that they must remove. Several advantages
include: aerobic composting reduces volume and
converts biodegradable materials into stable, low-odor
end products; thermophilic temperatures of 54 OC (130"F)
to 71"C (1600F), achieved in the process, kill most weed
seeds and pathogens.
The physical form of cattle manures often does
not provide optimal composting conditions. Fresh
manure is too wet, and screened solids are usually too
low in N content and other fertilizer nutrients. Thus,
mixing materials from other sources may be required.
Supplies of manure, bulking and drying agents, as well as
market demand for the finished compost, should be
investigated before animal producers invest in
Animal agriculture often is perceived by the
public as having negative environmental effects, e.g.,
concern with swine units in North Carolina, Iowa, and
Missouri; poultry units in Georgia, Maryland, Alabama,
Arkansas, and Connecticut; cattle feedlots in Texas,
Oklahoma, Kansas, and Colorado; dairies in Wisconsin,
California, Florida, and Washington. Perceptions usually
emphasize manure threats to water quality but nuisance
concerns, especially odors and flies, are critical.
Agriculture is based on biological systems that
effectively process manure nutrients and other biomass in
cost-effective, environmentally acceptable ways. Most
animal producers utilize these systems effectively and
those with on-farm nutrient excesses are correcting them.
Manure nutrients are manageable and the recovered
fertilizer value can pay for a large part of the system costs
if agronomic recycling is utilized. The public sector
needs to be aware of this and to monitor agricultural
systems based on real concerns and not perception so as
not to impose unnecessarily costly processing
In many regions, the public is imposing more
strict nutrient application requirements on manure than
on commercial fertilizer. Actually, there appears to be
less likelihood of manure nutrient losses to ground and
surface water than from commercial fertilizer. Frink
(1971) indicated that rarely are the N recovery
percentages in crop plus soil from commercial fertilizers
as high as with the three lowest manure applications
reported in the Tifton, GA, experiments (Newton et al.,
1995). The reasons that recoveries with commercial
fertilizer systems (and some manure application systems)
often are only 50 to 70% of the N applied is due to
leaching or runoff during periods when crops are not
growing, volatilization of ammonia N, denitrification, etc.
Active roots are needed to utilize the fertilizer, which
often is applied when the crop is planted, or before, rather
than side-dressed in smaller applications as needed by the
growing crop. One major advantage of sprayfield
applications of manure-containing wastewaters, the
method used in the Tifton, GA, experiments, is that
nutrient applications are frequent, in small amounts, and
most is in soluble form that can be taken up quickly by
The urban population may benefit from an
assessment of the ability of agriculture to help process
urban wastes. That avenue has potential to reduce costs
of processing urban wastes and, at the same time, give
better environmental accountability to the public sector.
This already is happening, with some municipalities
managing agricultural land or contracting with farmers to
utilize treated wastewater (reclaimed water) and sewage
How important is it to create a partnership
between farmers and the public to recover and recycle
waste nutrients to create a more sustainable world? It is
more important to consider how agriculture can help
sustainability than it is to worry specifically about a
sustainable agriculture. Food production on our
remaining agricultural land must be increased. It is a
challenge to do that and maintain all of the other
environmental qualities that are important. Achieving
those desired environmental qualities will require some
regulations. However, skillful use of incentives and
regulatory standards based on desired outcome rather
than process will give farmers much more freedom to
increase food production while at the same time
demonstrating environmental accountability.
Anonymous. 1984. Nutrient Requirements of Beef Cattle
(6th Ed.). National Academy Press,
Anonymous. 1989. Nutrient Requirements of Dairy
Cattle (6th Rev. Ed.). National Academy Press,
Frink, C.R. 1971. Plant nutrients and water quality.
CSRS/USDA Agric. Sci. Rev. 9(2): 11.
Gallaher, R.N., T.A. Lang, and H.H. Van Horn. 1995.
Estimation of N and P in Florida dairy
wastewater for silage systems. pp. 72-76 In
W. L. Kingery and N. Buerhing (eds.). Proc.
1995 Southern Conservation Tillage
Conference for Sustainable Agriculture.
Office Agric. Communic., MAFES,
Mississippi State Univ., Mississippi State,
Henry, G. M., M.A. DeLorenzo, D.K. Beede, HH. Van
Horn, C.B. Moss, and W.G. Boggess.
1995. Determining optimal nutrient
management strategies for dairy farms. J. Dairy
Morse, D., H.H. Head, C.J. Wilcox, H.H. Van Horn,
C.D. Hissem, and B. Harris, Jr. 1992. Effects
of concentration of dietary phosphorus on
amount and route of excretion. J. Dairy Sci.
Newton, G.L., J.C. Johnson, Jr., J.G. Davis, G.
Vellidis, R.K. Hubbard, and R. Lowrance.
1995. Nutrient recoveries from varied year
round application of liquid dairy manure on
sprayfields. In Proc. Florida Dairy Production
Conf., Dairy and Poultry Sci. Dept., University
of Florida, Gainesville, FL.
Tomlinson, A.P., W.J. Powers, H.H. Van Horn, R.A.
Nordstedt, and C.J. Wilcox. 1996. Dietary
protein effects on nitrogen excretion and
manure characteristics of lactating cows.
Trans. ASAE 39(4):1441.
Van Horn, H.H., G.L. Newton, and W.E. Kunkle. 1996.
Ruminant nutrition from an environmental
perspective: Factors affecting whole-farm
nutrient balance. J. Animal Sci. 74:3082-
Van Horn, H.H., R.A. Nordstedt, A.V. Bottcher, E.A.
Hanlon, D.A. Graetz, and C.F. Chambliss.
1991. Dairy manure management: Strategies
for recycling nutrients to recover fertilizer
value and avoid environmental pollution.
Florida Coop. Ext. Serv. Circ. 1016,
Van Horn, H.H., A.C. Wilkie, W.J. Powers, and R.A.
Nordstedt. 1994. Components of dairy
manure management systems. J. Dairy Sci.
Table 1. Estimated range in N, P, and K harvests in crops at a given DM yield due to variation in composition.
Yields N harvests P harvests K harvests
Crop Wet DM CP% % of DM lb/a % of DM lb/a % of DM lb/a
Corn silage 18.0 6.0 9.0 to 13.0 1.4 to 2.0 168 to 240 .22 to .47 26 to 57 1.0 to 1.5 120 to 180
Rye or wheat haylage 6.0 3.0 16.0 to 21.0 2.6 to 3.3 156 to 198 .23 to .50 14 to 30 .7 to 1.5 42 to 90
Bermuda grass hay 6.0 5.0 11.0 to 18.0 1.8 to 2.9 180 to 290 .20 to.34 20 to 34 1.3 to 2.2 130 to 220
Forage Sorghum silage 18.0 6.0 8.0 to 12.0 1.3 to 1.9 156 to 228 .22 to .44 26 to 53 1.0 to 1.5 120 to 180
Alfalfa haylage 10.0 5.0 18.0 to 25.0 2.9 to 4.0 290 to 400 .22 to .49 22 to 49 1.5 to 2.5 150 to 250
Perennial peanut haylage 10.0 4.0 14.0to22.0 2.2to3.5 176to280 .21 to.39 17to31 1.5to2.2 120to 176
'Ranges obviously exist in wet weight and dry matter (DM) yields. Farmers should use yield histories to estimate yields and their own composition history, if known.
100 from soil
Harvested from 1.0
acre (12.9 ton DM)
392 in milk 12
109,800 Ib millk 4 newborn calves
and weight gain
Figure 1. Example N budget for dairy manure system. Bold numbers represent pounds of N. Crop yield data are from experiments at Coastal Plain Experiment
Station at Tifton, GA; excretion data from University of Florida experiments. Figure adapted from Van Horn et al. (1996).
Organic Farming Practices
*J.J. Ferguson and M. Mesh
Organic farming was described as a system
prior to World War I by Sir Albert Howard who taught
that except for "natural phosphate rock and limestone,
imported off-farm plant nutrients should be avoided".
During World War II, J.I. Rodale applied these methods
on an experimental organic farm in Pennsylvania and
published Organic Farming and Gardening magazine
which, along with other Rodale Press publications,
popularized organic farming. In the 1970s, regional
organic groups like the California Certified Organic
Farmers, Oregon Tilth, the Organic Growers and Buyers
Association, and other groups in the U.S., Canada, and
Europe established standards for organic production and
certification. In the 1980s, Florida Certified Organic
Growers and Consumers, Inc. (FOG) was formed in
Gainesville and has become the major organic certifying
agency in this state, certifying 71 out of 88 organic
enterprises in Florida (Anon., 1997). On the national
level, the Organic Foods Production Association of North
America developed as the major trade association in the
1980s, representing growers, shippers, processors,
certifiers, distributors, and retailers. The International
Association of Organic Agriculture Movements
(IFOAM) has established international production,
processing, and trading standards, and represents the
international organic movement in parliamentary,
administrative, and policy-making forums like the Food
and Agriculture Organization of the United Nations,
Increasing interest in organic farming prompted
passage in 1990 of the Florida Organic Farming and
Food Law and the federal Organic Foods Production Act.
The Florida law established a regulatory framework for
organic certification and created an organic food advisory
council to advise the Commissioner of Agriculture on
organic farming issues, licensing of certifying agents, and
policies to promote organic products. The federal law
provided for USDA to develop national standards for
organic crops, livestock, processing and handling;
establish a materials list of approved inputs; set up an
accreditation process for the review of certification
'.J. Ferguson and 2M. Mesh. 'Hort. Sci. Dept., Univ. of
Florida, Gainesville, FL. 2 FL. Certified Organic Growers
and Consumers, Inc., Gainesville, FL. Manuscript
received 25 March 1997. *Corresponding author.
Florida Agric. Exp. Stn. Journal Series No. R-01400.
agencies and establish protocols for imported organic
products. Since 1990, the USDA has obtained public
input in regional meetings throughout the U.S. in
developing recommendations made by a 14 member
National Organic Standards Board (NOSB), leading to
eventual rule-making by the USDA. Long awaited
implementation of the Organic Foods Production Act is
expected to bring nationwide standardization of organic
methods, materials and processing, stimulating industry
growth domestically and internationally.
Organic agriculture has been generally defined
as a "holistic system with the primary goal of optimizing
the health and productivity of interdependent
communities of soil life, plants, animals, and people".
Management practices are carefully selected with an
intent to restore and then maintain ecological harmony on
the farm, its surrounding environment and ultimately the
whole planetary system." (Anon., 1995a). Organic
farming is a subset of sustainable agriculture that stresses
ecological balance in agricultural and livestock
production by developing healthy soils, which is the basis
for organic production, and high quality crops and
livestock. Careful selection of crops and plant cultivars
complements continuous improvement of soil organic
matter and soil fertility, particularly through green
manuring and addition of composted materials, manures,
and rock minerals. Although organic certifying agencies
and NOSB tentative recommendations differ somewhat
in allowed, regulated, and prohibited practices, a general
review of current organic standards and certification
procedures will be presented here.
Certification focuses on intent (a farm
management plan), evidence (history of a 3-yr transition
period free of prohibited materials), and documentation
(soil, leaf and water analysis, crop plans, field history
sheets, receipts, and affidavits). At the heart of organic
management is the farm plan, including written strategies
for ecologically sound resource management, plans and
evaluations of farm management practices and tangible
improvements in the farming operation. This plan must
address soil, crop, and resource management, as well as
crop protection and maintenance of organic integrity
through growing, harvest, and post-harvest operations.
Buffer zones up to 30-ft and/or appropriate barriers must
separate organic from conventionally-farmed fields or
other lands subject to synthetic spray or fertilizer
programs. Separate records, physical facilities,
machinery, and management practices must be
established to prevent the possibility of mixing organic
and non-organic products. Areas may not be switched
back and forth between organic and non-organic
management practices. If individual fields are certified,
the entire farm must be certified within 5-yr of
certification of the first field, according to international
standards (IFOAM) but not according to those of some
U.S. certifying agencies. However, NOSB
recommendations leave this to the discretion of the
grower. In general, synthetic materials are prohibited,
but some synthetic materials are considered to be
compatible with the goals of organic agriculture and are
allowed. (e.g. pheromones and insecticidal soaps). A
transitional status, involving management without the use
of prohibited materials for 12-m before harvest, may also
be obtained by previously uncertified farms and livestock
operations. For "wild land," documentation is required
that the land has been pesticide-free for 3-yr, along with
a management plan. Abandoned fields or groves to
which no prohibited materials have been applied for 3-yr
will not be certified because of lack of active
Packets containing certification information (40
to 60 pages) can be obtained from certifying agencies for
$25 to $35, with additional first-year and annual renewal
fees ranging from $125 plus a flat 0.0025% of gross
annual sales which exceed $15,000 for one certifying
agency (Anon., 1996) to a sliding scale based on
projected sales for the first year and on actual gross sales
from previous years for another agency. In the latter case,
fees vary from 7.4% and 4.5% for first and second year
certification for sales of 0 to $5,000 to 0.5% and 0.4% of
total sales of $500,000 (Coody, 1994). Processors pay
0.5% of net invoice sales for certification and handlers
pay 0.1% of gross profit. Growers who sell less than
$5,000 annually may be exempt from certification under
future NOSB agency standards but will be required to
produce and handle organic products in accordance with
organic production and handling standards.
Animals must be raised for their life on organic
feed and pasture under living conditions that foster herd
and flock health, without the application of prohibited
drugs and substances, except as allowed. Livestock must
also be provided with living conditions that minimize
stress and are suited to individual and collective needs,
with enough room to comfortably sit up, lie down, groom
normally, turn around and stretch. Breeding stock may be
bought from whatever source, provided the animal is not
in the last third of gestation, but may be sold as certified
organic only if raised in compliance with organic
standards for one year following purchase. Dairy stock
purchased from non-certified sources is restricted. New
and certifiable herds should be fed a minimum of 50%
daily ration of organically grown feed for 6-m followed
by being fed 100% certified feed for 6 to 12 m
(depending on the certifier) prior to the milk being
certifiable. Antibiotics and Normanist are generally
prohibited in organic dairies and water for dairy animals
must be less than 10 mg nitrate N per liter. Plastic
roughage, urea, intentional manure refeeding, and similar
practices are prohibited. Stacked cage confinement and
overcrowding of poultry is prohibited, and laying stock
must be managed in accordance with organic production
standards for at least 4-m before eggs can be certified.
Although certified organic meat products can be
produced and sold in-state, final USDA rules on organic
meat production must first be promulgated before
interstate shipment of these products can occur, creating
additional temporary marketing problems for organic
beef, poultry, and other products.
A basic tenet of organic farming is that a healthy
soil produces healthy plants. Accordingly, application of
soil amendments and fertilizers, especially soluble ones,
must be judged by the criteria of soil health and crop
requirements, for optimum, not maximum, production.
Soil fertility is maintained by managing organic matter
and mineral content through tillage, crop rotation,
incorporation of green and animal manures, and addition
of soil amendments and natural fertilizers like rock
minerals. Crop rotation includes alternation of sod and
row crops and crops which do not share similar pest
complexes; N-fixing crops; green manure crops, cover
and nurse crops; alternation of heavy and light feeders
and use of plants with allelopathic or mineral
accumulating properties. Tillage is used to control
weeds, disrupt pest and disease cycles, and improve
nutrient levels, tilth, and organic matter. Mono-cropping
is prohibited, with two-crop rotation regulated and a
three-crop rotation accepted as a minimum. Plant tissue
and soil testing, including organic matter content, levels
of macro and micronutrient, pH, cation exchange
capacity, soil texture, bulk density, and water infiltration
rate, are used to monitor soil health and indicate the
direction of a soil management program. Animal
manures, especially chicken manure, are the primary
fertilizer used by organic growers but only as a
supplement to other soil building practices. Records
must be maintained on manure type, source and
application date, site, method, and rate. Composted
rather than aged or raw manure is encouraged, preferably
produced on-farm and if produced off-farm, free of
contaminants. Some certifying agencies specify that fresh
manure be applied only when soil temperatures are
greater than 50*F or higher, moisture content between
field capacity and wilting point, and that application must
not result in contamination of surface or ground water or
in excessive nitrate concentrations in produce. Fresh
manure may not be used on crops destined for human
consumption less than 4-m before harvest. Manure aged
by the producer 90-d or more can be applied 30-d before
harvest of such crops. Approved N sources include green
manures and animals manures, N-fixing crops,
composted materials, and N-fixing organisms, with
certifying agencies differing on recommendations for fish
emulsion, vegetable meal, bone meal, and other animal
by-products. Although certifying agencies generally
prohibit Chilean or calcium nitrate (16-0-0), the National
Organic Standards Board recommends that this material
be limited to not more than 20% of the total N supplied
to a crop. Furthermore, farmers must develop strategies
to substantially reduce the use of Chilean nitrate over
time. Approved P sources include colloidal and rock
phosphate, with synthetic materials like ortho phosphoric
acid (0-50-0), superphosphate (0-20-0) and triple
superphosphate (0-46-0), prohibited, as are other
excessively soluble and acidfying materials with a high
salt index. Approved K sources include rock dust
(granite, feldspar, greensand), mined potassium sulfate,
sulfate of potash magnesia (sulfamag or langbeinite) and
kainite. Application of biosolids is regulated by some
certifying agencies and prohibited by others.
Organic production methods apply to the entire
life of the plant. Seedlings and other planting stock
should not be treated with any prohibited materials.
However, use of planting stock treated with synthetic
materials is regulated if organic materials are not
available. Transplants must be organically grown but
some certifying agencies allowed conventionally-grown
transplants for strawberries, caneberries, potatoes, garlic,
shallots, and bare-root nursery stock for perennials.
Organic management for 1-yr prior to harvest is required
for perennial planting stock (tree fruits, grapes and small
fruits of genus Rubus, Ribes, and Vaccinium) which are
not produced from organic stock. In greenhouse
production, lumber treated with copper-chromium
arsenate is classified as a restricted material but can be
used where plant leaves or roots do not contact such
treated wood. Organic and non-organic sites must be
separated by an impermeable wall and ventilation
systems must ensure that prohibited materials do not drift
from non-organic to organic production sites. Apiaries
must be located on certified land more than two miles
from areas like golf courses, major townsites, cities,
major traffic polluting areas, garbage dumps or crops
sprayed with prohibited pesticides that could contaminate
DISEASE AND PEST MANAGEMENT
Careful management, use of resistant varieties,
timing to avoid cycles of pest emergence, crop rotations,
inter-cropping, avoidance of excessive fertilization, and
general maintenance of soil health is the first line of
defense against weeds, pests, and disease. Mechanical
controls, such as traps, repellant crops, vacuuming, water
jets, and physical and sound barriers are generally
recommended as are the release of natural predators and
parasites, mating disruptors, and the creation of
environments fostering wild predators such as birds,
toads, and snakes. Sprays including insecticidal soaps,
microbial sprays, rock powders and diatomaceous earth,
herbal preparations, dormant oil sprays in orchards,
solutions of pureed insects or plants used as repellents are
allowed. Botanical and other natural insecticides such as
pyrethrum, rotenone, sabadilla, quassia, ryania, and neem
that have broad-spectrum effects are generally regulated.
Weed management includes prevention, avoidance and
sanitation; mechanical methods including tillage discs,
choppers, mechanical hoes, and non-tillage rotary
mechanical mowers, sickle-bar mowers, and devining
equipment; grazing, including weeder geese and animal
rotation in pastures; heat treatments, including flame hoes
with gas and superheated water, mulches, including use
of organic material, intercrop plants as well as covers of
different types; crop rotation and smother crops.
Polycarbonate plastic mulches (polypropylene and
polyethylene), mulching with recycled newspaper and
magazines containing inks and dyes and herbicides from
naturally occurring fatty acids are regulated as are
polyvinyl chloride plastics. When inadvertent
environmental contamination or pesticide drift occurs,
tolerance levels are set at no more than 5% of
Environmental Protection Agency (EPA) tolerance levels,
with responsible private parties liable for damages.
GENETICALLY MODIFIED ORGANISMS
Genetic engineering refers to organisms "made
with techniques that alter the molecular or cell biology of
an organism by means that are not possible under natural
conditions or processes. Genetic engineering includes
recombinant DNA or RNA techniques, cell fusion,
micro-and macro- encapsulation, gene deletion and
doubling, introducing a foreign gene, and changing the
positions of genes but not breeding, conjugation,
fermentation hybridization, in-vitro fertilization, and
tissue culture" (Anon., 1995b). Genetically-engineered
organisms and irradiation of crops are prohibited, but the
results of classical plant and animal breeding are allowed.
Genetic engineering is prohibited in order to guarantee a
common standard for all organic farmers and consumers,
many of whom are both philosophically opposed and
wary of the Pandora's box this approach may open.
Artificial insemination is also allowed but not embryo
Although state Department of Agriculture and
certifying agencies maintain data for organic certification,
farm location, acreage farmed, and commodities grown,
it is difficult to obtain accurate information, especially on
crop production, and sales. According to a recent Florida
Department of Agriculture listing (Anon., 1997), 88
enterprises were certified organic by 1997 by five of the
six certifying agencies licensed in Florida, with acreage
and crops of only 67 enterprises specified. Thirteen of
these 67 firms were juice, fruit, and vegetable packers
and processors. Of the remaining 54, 52 were farms
producing fruit and vegetable crops on 2,836 acres (27
citrus groves on 1,941 a; 17 vegetable farms on 740 a,
with two more enterprises on 15,267 a or 84% of the
total Florida organic acreage, in wilderness crops (saw
palmetto berries and herbs).
More specific information indicating trends is
available from California, which has an older and better
organized organic farming industry (Klonsky and Tourte,
1997). In 1992-93, in California, 1,159 organic farmers
sold more than 70 individual commodities produced on
45,493 a with sales of $75.4 million. Fruit and nut crops
and vegetable crops represented 96% of the gross sales
on 75% of all acreage. Fruit and nut crops comprised
42% of the total organic acreage, vegetable crops about
31%, and field crops 18%.
Vegetable crops were the highest value
commodity with $37.7 million, representing 50% of the
total gross sales (Table 1). Although approximately
4,050 U.S. organic crop and livestock producers on 0.2%
of total U.S, farms were certified by 1994 on
approximately 0.1% (1,127,000 a) of total U.S.
agricultural land (Dunn, 1995), consumer and farmer
interest in organic farming is increasing because of
personal concerns about food safety and environmental
stewardship as well as marketing opportunities. With
dramatic sales increases predicted for this well defined
and documented agricultural sector, especially in large
urban markets (Burfield, 1996), national agricultural
policy, regulatory and marketing leaders are watching this
emerging industry carefully.
Anonymous. 1995a. National Organic Standards Board
Documents. U.S. Department Agriculture,
Agriculture Marketing Service,
Transportation and Marketing Division,
Washington DC. 8pp.
Anonymous. 1995b. National Organic Standards Board
final recommendation addendum number 10:
general organic food labeling standards. Austin,
Anonymous. 1996. Policy and Procedures Manual,
Certification Standards, Materials List. Florida
Certified Organic Growers and Consumers,
Gainesville, FL. 53pp.
Anonymous. 1997. Licensed Organic Certifying Agents
for FY 1996-97. Florida Department of
Agriculture and Consumer Services.
Burfield, T. 1996. Market overview; retailers staking
claims. The Packer. 44:D1.
Coody, L.S. (ed.). 1994. Oregon tilth certification
standards and procedures manual. Tualatin,
Dunn, J.A. 1995 Organic food and fiber: an analysis of
1994 certified production in the United States.
USDA, Agric. Marketing Ser., Transportation
and Marketing Division, Washington,
Klonsky, K., and L. Tourte. 1997. Vegetables, fruits and
nuts account for 95% of organic sales in
California. California Agriculture 50:9-13.
Table 1. Characterization of California organic farms by commodity group, 1992-93*
Commodity group Number of Median Median Median
farms a sales sales
Vegetable crops 293 2.3 9,500 3,250
Fruit and nut crops 652 6.0 6,000 1,393
Field crops 25 80.0 50,000 361
Combined fruit, nut, and 70 3.3 5,235 2,009
Livestock, layer hens and 5 N/A 5,000 N/A
Nursery and flowers 1 3.0 10,000 3,333
Mixed commodity 113 9.0 13,000 1,406
All farms 1,159 5.0 7,500 1,685
* Klonsky and Tourte, 1997.
Converting Conservation Reserve Program Contracts To Cropland in Oklahoma
*J.H. Stiegler, T.H. Dao, and T.F. Peeper
Holders of the 1.3 million acres of Conservation
Reserve Program (CRP) contracts in Oklahoma will have
to choose the future use of this land in 1997. Many of
these acres will eventually be converted back to cropland
because they will not meet the requirements of CRP-2.
There is a general lack of knowledge and no best
management practices guidelines on how these highly
erodible lands should be economically converted back to
cropland and still remain in compliance. A multi-agency
research and demonstration project was funded by
Southern Region USDA Sustainable Agriculture
Research and Education Program/EPA Agriculture in
Concert with the Environment Program (SARE/ACE) in
1994. The objectives were: 1) to identify dryland
production systems for converting the CRP grass (Old
World Bluestem [OWB]) (Andropogon gerardii) to
annual production of wheat (Triticum aestivum L.) and 2)
to evaluate the profitability and sustainability of the
production system compared to managing the grass for
MATERIALS AND METHODS
Field-Scale Evaluation of Cropping Systems
Field studies were conducted on two CRP fields
under contract since 1987. The Forgan, OK, site is 160
a of Dalhart fine sandy loam, 1-3% slope in Beaver Co.
(NW) with 18 in of annual precipitation. The Duke,
OK, site is 160 a of LaCasa-Weymouth clay loam, 1-3%
slope in Jackson Co. (SW) with 29 in of annual
precipitation. In May, 1994, 1995, and 1996, 25 to 30 a
were either control burned or mowed and baled to
remove the old grass growth. Four replications of 1-a
plots were established at Forgan, while one 4-a and three
0.5-a plots were established at Duke. At Forgan, sweep
tillage (ST) consisted of undercutting the existing sod
with a 36 in V-blade sweep in mid-July. No other tillage
was performed during the summer of 1994, but in 1995
an offset disking was needed to control sod regrowth and
to smooth the seedbed prior to planting. In 1996, the
'J.H. Stiegler, 'T.F. Peeper, and 'T.H. Dao, 'Oklahoma
State University, Stillwater, OK, and 2USDA-ARS,
Bushland, TX. Manuscript received 28 March 1997.
tillage was further modified to include two diskings after
the sweep tillage. At Duke, disk tillage (DT) consisted of
offset disking twice to kill and partially incorporate the
sod in July of 1994, 1995, and 1996 and one tandem
disking was performed prior to planting in October. In
all the no-till (NT) plots, the OWB grass was treated with
1 lb/a of glyphosate in July or August and re-treated with
an additional 1 lb/a of glyphosate in September before
drilling the wheat. In 1996, the OWB grass was treated
once with 2 lb/a of glyphosate in July. All glyphosate
was applied with a surfactant and ammonium sulfate. A
Tye 10-in-spacing (1994) or Great Plains 7-in-spacing
(1995, 1996) no-till drill was used to plant all plots with
70 lb/a of wheat seed and place 100 lb/a of 18-46-0 with
the seed. Sixty lb/a ofurea-N was applied broadcast at
planting or topdressed to plots in March. The wheat was
treated in November, 1994 with 10 oz parathion for fall
armyworms (Laphygamafrugiperda), and in March of
1994 and 1996 with 1/6 oz of chlorsulfuron and 0.25 lb
chlorpyrifos for broadleaf weed and greenbug control,
respectively. Grain was harvested using a plot combine.
The ST, DT, and NT plots were maintained after wheat
harvest each year and replanted. The ST and DT plots
were swept or disked once in July and again in
September. The NT plots were treated with 1 lb/a of
glyphosate in September and all plots were annually
planted back to wheat.
Small plot herbicide and tillage methods for re-
cropping CRP lands to winter wheat
Plots (20 ft x 25 ft) were established at both
CRP experimental sites without any pre-treatment and
treatments were applied directly to the standing OWB
biomass to evaluate the effectiveness of selected tillage-
herbicide combinations to kill the sod. Two hundred lb/a
of 18-46-0 and 100 lb/a ofurea-N were applied to plots
that were either moldboard plowed, disk plowed, or no-
tilled. Glyphosate was applied at 0.25, 0.5, 0.75, 1.0, and
1.5 lb ai/a and glyphosate-2,4-D mixture (Landmaster
BW) at 40 and 54 oz/a were applied across the plots
before tillage in either May, June, or July. All tilled plots
were disked once before planting wheat at a rate of 80
Ib/a. The wheat was topdressed with 100 lb/a ofurea-N
in March. Old world bluestem, weeds, wheat vigor, and
stand counts were made periodically. Yields were
determined with a plot combine.
Fertilizer requirements of winter wheat in re-
cropping CRP fields
Plots (20 ft x 25 ft) were established to evaluate
the effects of N and P fertilizers for winter wheat
production in re-cropping CRP lands and the
decomposition of the grass residues. OWB was treated
with 1 lb/a of glyphosate in mid June. Liquid fertilizer
was applied to the biomass before the primary tillage
treatments of either moldboard plowed, disk plowed, or
no-tilled. Fertilizers applied were: 0 lb/a N, 100 lb/a N
as 34-0-0, and 100 lb/a N + 50 lb/a ofP,20. The plots
were planted to wheat at a rate of 80 lb/a. Visual ratings
of wheat vigor and stand density were made periodically
during the growing season. Grain yields were determined
with a plot combine.
RESULTS AND DISCUSSION
Wheatyield data for 1994 and 1995 from field-
scale plots are shown in Table 1. The 1994 wheat yields
ranged from 13 bu/a to 26 bu/a, with the higher yields at
Duke. Due mainly to drought conditions in 1995, wheat
yields were much lower, ranging from 4 bu/a to 14 bu/a.
In general, (NT) wheat yields were significantly higher
than ST yields at Forgan in 1994 and the disk (DT) plots
at Duke in 1995. At Duke, better herbicide suppression
of OWB and soil moisture improved wheat emergence
and growth in both systems. Although the crop seemed
to grow better under the high residue-NT system, grain
yields were not significantly different. Delays in
herbicide suppression and tillage of the grass in 1994
depleted soil moisture, especially in the ST plots at
Forgan. Sweep tillage was found to be an economically
effective means of controlling OWB. If the soil remained
dry for several days following tillage and the air
temperatures were high, more than 90% of OWB was
killed. Rates of glyphosate up to 1.5 lb/a were less
reliable in suppressing OWB than tillage. Except when
applied in July, glyphosate did not effectively control the
grass in small plots (Table 2). Field applications at rates
up to 2.0 lb/a were also less than satisfactory.
In small plots without prior removal of old grass
growth, wheat yields were higher than in similar field
studies. This is due to the larger amounts of N fertilizer
applied. In this study, wheat yields from disk and
moldboard tillage plots were significantly higher than NT
yields (Table 3). The data also shows that glyphosate
rates higher than 0.5 lb ai/a did not significantly increase
wheat yields. Applying glyphosate before tillage of the
plots did increase wheat yields in disked but not in
moldboard plowed plots. Large amounts of surface
residue interfered with seed placement, row closure, and
soil-seed contact during planting. Stand counts were 2.4,
5.8, and 6.6 plants/ft2 for NT, disk, and moldboard,
respectively. Glyphosate applied to the thick residue
also reduced its effectiveness in controlling OWB.
In nutrient depleted CRP fields, N fertilizer is
essential for producing acceptable wheat yields
regardless of tillage method. Data showing wheat yields
from fertilized and unfertilized plots are presented (Table
4). Unfertilized small plots yielded 34% and 60% of N-
fertilized plots at Forgan and Duke, respectively.
Additions of P appeared to increase wheat yields but the
amounts were not significant When the old grass growth
was not removed before tillage and herbicide application,
highest wheat yields were attained with moldboard
Although it is highly desirable to conserve as
much of the fixed C in the surface mulch, there appears
to be too much mulch to effectively plant wheat either
minimum or NT and get acceptable stands and crop
yields unless the mulch is either burned or mowed and
baled. A controlled bum is an inexpensive and effective
way to remove the old grass growth and the resulting new
grass growth is controlled more effectively with
herbicides. Moldboard tillage is an excellent way to bury
the old grass growth and kill the grass ifpre-treatment is
not done. With high amounts of supplemental fertilizer,
good wheat stands and high crop yields were attained, but
this clean till practice makes the soil more susceptible to
wind and water erosion and the tillage greatly enhances
the mineralization of the residual carbon. Sweep tillage
is.an effective minimum till system that provides good
OWB control and loosens the soil surface. No-till wheat
production into control burned and killed OWB sod
offers the highest degree of soil erosion control and
maintenance of organic matter. In most cases, wheat
yields have been as good as conventional or minimum till
production. However, it is more difficult and costly to
chemically control perennial, warm season grasses.
Early suppression of OWB is vital to crop production in
much of this semi-arid region. Adequate lead time is
necessary to allow for partial decomposition of the
organic residue and to re-supply the soil profile with
moisture. The wheat responses are very dependent on the
soil and climate.
Economic evaluation of the cropping systems
and livestock comparisons have not been completed. The
lower wheat yields of these highly erodible lands in a
semi-arid region suggests that wheat will provide a
negative return due to the high costs of conversion. Many
farmers would be better advised to not convert to crop
production. They should be advised to re-enroll these
acres in CRP-2. If they are unsuccessful in getting into
the program, then they should consider developing a
forage and livestock enterprise. Under managed
conditions, the OWB will produce substantial forage that
should yield 100 to 150 lb beef/a and a positive cash
flow. For many farmers, the final decision about post-
CRP land uses will depend on prices of crops and
livestock. Loss of government payments in 7 yr will
cause many to re-evaluate their earlier decisions.
Table 1. Dryland wheat yields on former CRP lands.
Location Year Tillage System' First year Second-year
Forgan, OK 1994 ST 13b3
19952 ST 12a 3a
NT 4b 2a
Duke, OK 1994 DT 24a
19952 DT 7b 6b
NT 14a 14a
'ST = sweep tillage; DT = disk tillage; NT = no-till
'Drought of 1995-96
'Letters represent crop yields in each year that were significantly different at p = 0.05
Table 2. Percent control of Old World Bluestem in CRP fields four wk after application date shown.
Roundup rate DUKE. OK FORGAN. OK
lb/a June July May July
0.25 33 10 12 37
0.50 59 39 13 47
1.0 73 69 13 87
1.5 61 83 13 93
LSD.o 13 LSD.o5 9
Table 3. Effects of tillage and herbicides on suppression of intact OWB sod.
TREATMENT 'A B C D E F G
Forgan, OK ------------------------ bu/a --------------------------
No Till 19 20 24 24 24 17 18
Moldboard 29 28 32 31 30 30 31
Disk 27 28 28 31 27 31 31
No-Till 17 19 21 24 26 21 18
Moldboard 37 39 39 36 40 38 37
Disk 34 35 39 36 38 38 36
'A=Gly, 0.25 Ib/a; B=Gly, 0.50 lb/a; C=Gly, 0.75 lb/a; D=Gly, 1.0 lb/a; E=Gly, 1.5 lb/a
F= Gly-2,4D, 40 oz/a; G= Gly-2, 4D, 52 oz/a
Table 4. Effect of tillage and fertilizer on wheat yields (small plots)'.
Fertilizer No-till Moldboard plow Disk Mean
Forgan, OK ------------------------------bu/a ---------------------------------
0 1 10 6 5.7a
100 lb N/a 14 26 24 21.3b
100 lb N + 50 lbP /a 15 28 25 22.7b
0 8 20 14 14.0a
100 lb N/a 22 30 28 26.7b
100 lb N + 50 b P2OA/a 26 32 29 29.0b
'No removal of the old OWB growth before tillage or spraying.
Telogia Creek Conservation Tillage Project
*B.F. Castro, J.C. Love, B.R. Durden,
F. Johnson, and H. G. Grant
A Best Management Practice
demonstration project on crop and pasture land in
the Telogia Creek Watershed was conducted by
making reduced tillage equipment available to
farmers, establishing on-farm demonstration plots,
and holding field days to demonstrate and evaluate
reduced tillage, new conservation tillage and new
subsoil tillage technology. An evaluation of a Dyna
Drive, a new rotary surface ground driven cultivator,
and a Terra Max subsoiler with a newly designed
bent-leg shank was performed. Primary tillage
demonstrations of the Dyna Drive revealed that this
implement can reduce the number of trips required
for soil preparation. In normal field conditions where
80 to 90% field residue exists, one pass of the Dyna
Drive left an excellent seed bed while leaving 30 to
50% residue. The Terra Max subsoiler was
successful in disrupting existing hard pans and
reducing soil compaction. Substantial growth
response was observed in winter annual and summer
perennial forage plots where subsoiling was
The focus of this grant project was on Gadsden
County and North Florida area beef cattle producers,
although the project was not restricted to this audience.
Best management practices (BMPs) for all sectors of
agriculture are currently being evaluated and established
because of federal and state mandates. The
Environmental Protection Agency estimates that
agriculture accounts for two thirds of non-point sources
of pollution nationwide. One significant way to reduce
non-point source pollution from farm fields is to
implement a conservation tillage system. Livestock
producers in North Florida often utilize conventional
'B.F. Castro, 2.C. Love, 'B.R. Durden, 'F. Johnson, and
'H. G. Grant, 'Gadsden County Extension Service, IFAS,
Univ. of Florida, Quincy, FL, 2Florida Department of
Agriculture and Consumer Services-Office of Agriculture
and Water Policy, Tallahassee, FL, 'USDA Natural
Resource Conservation Service, Quincy, FL. Manuscript
received 26 March 1997. *Corresponding author.
tillage equipment in the soil preparation for planting cool
and warm season forages. The planting of forage crops
generally involves a mulch tillage system that involves
tilling the complete field surface with some type of tillage
implement such as a disk harrow, chisel plow, turn plow,
field cultivator, combination tool or rotovator. Often
fields are left with little surface residue to combat wind
erosion, water erosion, and the leaching of nutrients or
chemicals. Cattle producers experience forage yield
losses due to the constant treading of hooves that causes
severe soil compaction in most soils. Many of the existing
tillage systems do not go deep enough to disrupt soil hard
pans. Project goals were to identify BMPs that reduce soil
erosion, improve water quality, reduce fuel consumption,
while at the same time, improve soil health and crop
According to the Natural Resource
Conservation Service (NRCS), conservation tillage is
defined as any tillage method that leaves 30% of the field
covered with residue after planting. Previous research
had demonstrated that the Dyna-DriveR (registered
trademark of Alamo Group Inc., Gibson City, IL),
described as a rotary surface cultivator that was designed
in England and widely used throughout Europe, could
produce a very level, small clod and residue protected
seedbed (Smith,1995). Studies have shown that quality
seedbeds could be produced with one pass of the Dyna-
Drive into corn (Zea mays L.) stubble (Smith, 1995.).
Subsoiling increases yields while doing
minimal damage to soil strength, while conventional
tillage creates significant damage to soil strength
(Busscher et al.,1995.). Deep tillage that does not disturb
surface residue or existing forages is needed in many
Southeastern Coastal Plain soils to disrupt subsoil hard
pans that restrict root growth (Khalilian and Hallman,
1996.). North Florida cattle producers have not
established BMPs that reduce soil compaction and
effectively disrupt hard pans.
MATERIALS AND METHODS
In the Spring of 1995, a cooperative project
among the Gadsden Soil and Water Conservation
District, Gadsden County Extension Service, Florida
Department of Agriculture and Consumer Services'
Bureau of Agriculture Water Policy, and Gadsden County
NRCS was initiated. Grant funds were secured through
the Florida Department of Environmental Protection's
Section 319 Program to do a conservation tillage
demonstration project in the Telogia Creek watershed and
Gadsden County. The purpose of the project was to
evaluate and demonstrate new technology and establish
BMPs that enhance soil health and increase forage yield.
A project goal was to show farmers how conservation
tillage and deep tillage can reduce nonpoint source
pollution from cropland and pasture land. The project ran
from April 1995 to April 1997 and included a
conservation tillage equipment loan program, field days,
A new, eight-ft-wide (8' 7"), ground-driven,
rotary-surface cultivator called a Dyna-Drive and a new
bent-leg (parabolic and curved) three-shank subsoiler
called a Terra MaxR (registered trademark of Worksaver,
Inc., Litchfield, IL) was purchased to loan to farmers to
allow them to evaluate reduced tillage practices on their
farms. The Dyna-Drive is suitable for conservation tillage
as well as conventional tillage and can be used for
seedbed preparation, chemical incorporation, pasture
renovation,and overseeding. The Dyna-Drive is ground-
driven and it is designed to be operated at six to eight-
mph. A TyeR (registered trademark) grain drill box
(seeding attachment) with hydraulic-driven motor was
attached to the Dyna-Drive to allow seedbed preparation
and seeding in one pass. Seed tubes were designed to
drop seed in front of the crumbler roller, just behind the
twin rotor tines. The attachment of a seeder like this is not
necessarily recommended by either company, the
manufacturers of Dyna-Drive or Tye equipment.The
project provided a custom operator who used a 110 PTO
horsepower tractor to operate the equipment.Tractor
power selection was based on soil conditions, depth of
tillage, tractor speed requirements, and manufacture
suggestions. The Terra Max subsoiler manufacturer
literature states that their patented, narrow, helical shank
design conditions the soil to a depth of 20 in, leaving soil
structure intact. The Terra Max was set up with three
shanks spaced at 30 in. The Terra Max was equipped
with coulters to slice residue in front of the shanks and an
attached roller-conditioner to level the raised soil after
Demonstration plots were established with the
Dyna-Drive/seeder combination on crop land, pasture
land and hay land. Plots were seeded with oat (Avena
saliva L.), rye (Secale cereal L.), ryegrass (Lolium
multiflorum L.), and clovers. Also the Dyna-Drive was
used to incorporate 'Alicia' bermudagrass (Cynodon
dactylon L.) sprigs on cropland while simultaneously
Demonstration plots with the Terra Max
subsoiler were established on temporary pastures where
small grains are planted in the fall and annual crops are
planted in the spring or native forages such as crabgrass
(Digitaria spp.) are grazed in the summer. Deep tillage
is not a common practice on these fields and pastures.
Subsoil demonstration plots were also established on
permanent pastures and hayfields, which were
bermudagrass and bahiagrass (Paspalum notatum L.).
An established bermudagrass pasture/hayfield was
subsoiled in strips leaving non-subsoiled strips in the
field and was followed by a 7-in-spacing grain drill
(Dyna-Drive was not used here) where ryegrass and two
varieties of clover, Cherokee Red and Dixie Crimson,
were planted in the fall. The Cherokee Red (Trifolium
pratense L.) and Dixie Crimson (T. incarnatum L.) were
not mixed, however, the individual clover varieties were
mixed with the same variety of 'Surrey' ryegrass and
clover performance was also evaluated where subsoiling
was and was not performed. A Dicky-John' (registered
trade name) Soil Compaction Tester was used to analyze
soil compaction through out the upper soil profile,
identify hard pan depths, and evaluate the before and after
effects of subsoiling.
RESULTS AND DISCUSSION
Forty-four farmers utilized either or both the
Dyna-Drive and the Terra Max through the loan program
that paid about 65% of the equipment operation costs.
Additionally, seven sites were donated by producers for
the purpose of demonstrating and evaluating this
equipment.The Dyna-Drive was used on approximately
300 a and the Terra Max was used on a little over 150 a.
Gadsden County soils are highly variable ultisols and
more sand content is generally the rule in the surface
profile and clay content is usually higher in varying
depths of these mostly mineral North Florida soils. Most
of the farm land this equipment was used on was upland
soils with loamy fine sand surface soils and sandy clay
loam to fine sandy clay subsoils. A few fields had some
loamy sands to coarse sand sections. Gadsden County is
not typical for most Florida soils as it borders the lower
Chattahoochee River Valley and its soils are typical of
many Coastal Plains Soils found in Georgia.
Under these soil conditions, the Dyna-Drive
performed well and the twin rotor tines that work the soil
appear to not suffer from abnormal wear. Based on
observational wear, the Dyna-Drive tines will have to be
replaced at about the same interval as a disk on a
conventional disk harrow,.
The Terra Max subsoiler did not stand up as
well under these soil conditions. After 150 a of use, three
sets of points had worn out and all three bent-leg shanks
had worn out There was not a close-by representative for
the Terra Max manufacturer and no one was aware that the
manufacturer has a solution for this excessive wear.
Worksaver Inc. Sales and Marketing Manager, Chuck
Bellew, stated that the Terra Max should have been
equipped with wear plates and chromium carbide points,
which the company has to offer to be installed to the
subsoiler shanks. Bellew stated that the Terra Max is
getting about 800 a of use with the wear plates and
chromium carbide points. With the wear plates installed,
the shanks should get thousands of acres of use (Bellew,
1997, personal communication).
Farmers were well satisfied with the
performance of the Dyna-Drive.The District NRCS
District Conservationist sampled 10 fields where primary
tillage was performed on a variety of cropping systems
and found the surface residue to be above 30% and
sometimes as high as 50%. In secondary tillage
operations and where residue was less than 50% to begin
with, surface residue did fall below 30%. Growers were
extremely pleased with how level the Dyna-Drive leaves
a field and how good the seedbed is after one trip over the
The Dyna-Drive was field tested on a cotton
field in the fall of 1996. In rank cotton (Gossypium
hirsutum L.) stalks of recently harvested cotton, the self-
cleaning tines worked quite well where the cotton stalks
were 5 ft or less. Where cotton stalks exceeded 5 ft or
more, the stalk coverage and burial of large stems was
not adequate in one primary trip. The stalks were still
somewhat green and contained high moisture,. Had the
stalks gone through a frost, the Dyna-Drive would
probably have performed better in cotton residue.
Compared to one pass of a disk harrow, the Dyna-Drive
was better in cotton stalks. The cotton stalks had not been
mowed. The conventional tillage practice is the mowing
of stalks which is followed up by discing. In cotton that
has not been allowed to get excessively high or too rank,
which usually causes severe lower boll rot and reduced
yields, the Dyna-Drive may be a good implement for
growers to consider. More research needs to be
The seeding of winter small grains by
simultaneously seeding with the attached (Tye) seeder
met with mixed results. In the fall of 1995, nine farmers
planted small grains for forage which were rye, ryegrass,
and oats. A small seed clover attachment made it where
clover could also be simultaneously planted. Four of the
nine farmers interseeded clover. Plantings in fall 1995
proved successful and good stands were achieved. In the
fall of 1996, 15 producers planted winter small grains
with this combination seeder and tillage implement.
There was a substantial dry period in October 1996, and
mixed results were achieved. Some stands of rye,
ryegrass, and oats were slow to establish and in some
cases, undesirable plant populations or stands resulted.
An inspection of the actual placement of seed in the soil
and seed soil contact was evaluated. The placement of
seed behind the tines and in front of the roller conditioner
was not leaving a substantial portion of the seed at a
satisfactory depth or with the appropriate seed to soil
contact, particularly where moisture was marginal for
germination. The broadcasting of rye, oats, or wheat in
front of the Dyna-Drive appeared to be a better method.
More uniform stands were achieved by spreading the
larger seeded small grains prior to tillage. Observations
of utilizing the attached seeding apparatus for planting
ryegrass and clover met with better results. Also, in
permanent pastures overseeded with the Dyna-Drive in
the Fall, the bermudagrass or bahiagrass was quicker to
re-establish in early summer as compared to conventional
tillage. More research is needed before precise
recommendations can be made for the practice of
simultaneously seeding in combination with ground
The Terra Max subsoiler was very effective in
reducing soil compaction and shattering hard pans. The
curved or bent-leg shank breaks up hard pans as it lifts
the soil above the shank point. With a one-half ('2)-in tip
installed on the soil compaction tester, readings in most
fields showed there was a definite hard pan at a 6- to 8-in
depth. Prior to subsoiling, soil compaction of hard pans
often measured above 300 psi. One subsoiling brought
hard pan zone readings to less than 100 psi. The 30-in
shank spacing seemed adequate, however, sometimes a
complete shatter was not achieved between shanks.
Communication with the manufacturer was made about
this possible problem. Their suggestion was that in order
to accomplish a more complete shank-to-shank disruption
of hard pans, off-setting shanks, which they sell as an
option, are the solution. The Terra Max tool bar is
designed for two in-line shanks, one is installed behind
the first One shank would curve left and the other would
curve right. These were manufacturer suggestions and
more research is needed. All of the three shanks used in
this project curved the same direction. A ridging effect
was created at the shank soil entry locations in permanent
pastures. The manufacturer stated this could be corrected
by removing the gauge wheels which would create more
down pressure on the roller-conditioner. It should also be
well noted that it takes considerable more tractor size or
horsepower to subsoil with bent-leg shanks versus
straight leg shanks.
The Terra Max yield response in three test plots
where subsoiling was compared to no subsoiling (other
tillage, seeding, and fertilization practices were identical)
increased forage yield. In a 1-a field that was strip
subsoiled in front of the Dyna-Drive, only a slight
marginal growth response was noticed in rye. In a
permanent bermudagrass pasture, a dramatic growth
response was observed where subsoiling was performed.
A 9-in average height advantage was observed, although
the grass height was somewhat up and down between the
shanks. In the ryegrass-clover mix demonstration where
subsoiling was followed by a grain drill, based on
observational results, total forage yield was about double
or twice as much (ryegrass and clover) as the control.
Both implements tested appear to be good BMP
candidates, while this equipment takes considerable
power to operate, both actually reduced energy use in
producing quality forage. The Dyna-Drive revealed that
this implement can successfully reduce the number of
passes needed for soil preparation in most field
conditions. In compacted permanent pastures, The Dyna-
Drive substantially outperformed conventional disk
harrows in the pulverization of sod. It leaves an excellent
seed bed while leaving a higher percentage surface
residue. Although more research is needed, it appears to
be a viable BMP implement. The Terra Max subsoiler
shattered hard pans, reduced soil compaction by as much
as 200 PSI and exhibited substantial growth response.
Because of improved internal soil characteristics,
drainage, permeability and the amount of surface residue
left, subsoilers of this design are worth considering as
conservation tillage tools.
Busscher, W. J., J.R.Frederick, and P.J.Bauer.l995Soil
strength for deep-tilled wheat and soybean
Doublecrop in the Southeastern Coastal Plain.
pp. 66-68. In W.L. Kingery and N. Buehring
(eds.) Proc. 1995 Southearn Conservation
Tillage Conference for Sustainable Agriculture.
SB 88-7. Mississippi Agr. and Forestry Exp.
Sta., Mississippi State, MS.
Khalilian, A., and R.R. Hallman. 1996. Energy
requirements of conservation tillage tools in
Coastal Plains soils. pp. 93-95. In Proc.
Conservation Tillage Conference for
Sustainable Agriculture, SP 96-07. Univ. of
Tennessee, Jackson, TN.
Smith, D. 1995. Just A Touch of Tillage. Farm Journal.
Nov. 1995. Special Section- Conservation
The Dyna-Drive is a very uncomplicated twin rotor
ground-driven tillage tool that has no PTO or gearbox.
The Dyna-Drive's front rotor is geared directly to the
ground and drives the rear rotor with a heavy duty roller
.,.* ., ... .; ; .^ ;:. .. .. .:..;.. ^.'.
Obstacles to Sod-Seeding Winter Annual Forages in Mississippi
*David J. Lang, Robert Elmore, and Billy Johnson
Winter annuals such as ryegrass (Lolium
multiflorum) provide outstanding forage during the fall,
winter, and spring months (October through May)
throughout the southeastern United States. Tillage
invariably increases the earliness and fall yield production
of ryegrass compared with any type of no-till or sod-
seeding (Lang andElmore, 1995; Lang et al., 1992; Lang,
1989). A general pattern of two to three months of
reduced growth of sod-seeded ryegrass in the fall
followed by equal or slightly increased growth in the late
winter and early spring as compared with ryegrass seeded
into plots that were disked has been observed (Lang,
1989; Brock et al., 1992; Ingram et al., 1993; Lang and
Various factors such as summer growth
removal, sod type and density, soil moisture, nutrient
immobilization (particularly N), insects, seedling
disease, soil type, and allelopathy may affect the success
or failure of sod-seeded ryegrass (Lang, 1993). Although
tillage may stimulate fall ryegrass growth, soil moisture
may be lost by exposing the bare soil to wind and solar
evaporation. Chemical summer fallow with glyphosate or
paraquat may conserve soil moisture; this has been
observed on the Prentiss sandy loam soil at Newton, MS.
In fact, seeding ryegrass into a killed volunteer annual
grass on the Prentiss soil has been found to be equal to or
greater than seeding into a disked seedbed, particularly
when late summer and early fall rainfall was limited
(Brock et al., 1992). Insects such as crickets (Gryllus
spp.), grasshoppers (Melanoplus spp.), and armyworms
(Pseudaletia spp.) have been suspected (but not verified)
of adversely affecting stand establishment in one out of
every four years according to a recently completed
researcher survey (Lang, 1997, unpublished). However,
stand density is generally observed to be similar in both
sod-seeded and tilled plots (Lang, 1989; Lang, 1993;
Lang and Elmore, 1995).
The objective of this study was to compare
results of several experiments over a number of years at
multiple locations from various ryegrass sod-seeding
'D. J. Lang, 'R. Elmore, and 'B. Johnson, IMississippi
State University, Mississippi State, MS and 2Coastal
Plain Branch Exp. Station Newton, MS. Manuscript
received 10 March 1997. Corresponding author.
experiments in order to identify various factors which
may be obstacles (challenges) to successful sod-seeeding
of winter annuals.
MATERIALS AND METHODS
Various sites, tillage practices, and summer
forage systems were utilized over several years at
different locations. Particular details about each study are
contained in the footnotes of each table along with its
reference citation if previously published. Sod type was
either volunteer annual grasses such as crabgrass
(Digitaria sp.), broadleaf signalgrass (Brachiaria
platyphylla), or permanent sod with bermudagrass
(Cynodon dactylon). Tillage practices included single or
double disking at 0, 30, or 60 d prior to seeding,
moldboard plow followed by disking and cultipacking,
rototilling followed by disking and packing, or seeding
directly into sod. Sod suppression and summer growth
removal treatments included herbage removal by haying
or grazing, herbicide burdown 1 to 30 d prior to
seeding, herbicide burdown followed by herbage
removal by mowing or fire, or sod-seeding without
herbage removal. Sites and soil types were Starkville, MS
(Savanna sandy loam or Marietta silt loam), Newton, MS
(Prentiss sandy loam), and Raymond, MS (Loring silt
loam). Each treatment was replicated four times and
experimental design was generally a randomized
complete block in small plots (6 ft x 18-24 ft), strips
within pastures, or replicated pastures. Analysis of
variance (ANOVA) was determined at each location by
year and over multiple years. Means were separated by
RESULTS AND DISCUSSION
Tillage improves the growth of winter annuals
sown into either summer annual sod (Tables 1 and 2) or
into bermudagrass (Table 3). Yield of winter annuals is
generally greater when sown into volunteer annual
grasses as compared with sowing into permanent sod
(Lang et al., 1992), which is in agreement with current
work reported in Tables 1-3. Permanent sods of
bermudagrass tend to be denser than annual sods which
may provide greater hindrance to seed to soil contact.
However, stand density has generally been reported to be
excellent regardless of the type of sod involved (Lang,
1989; Lang et al., 1992; Ingram et al., 1993; Lang and
Elmore, 1995). The difference in winter annual forage
growth between annual sods and permanent sods is most
likely due to the quantity of herbage and root mass
remaining after hay removal and herbicide burndown.
This material may contribute to nutrient immobilization
(e.g., N), contain inhibitory substances (allelochemicals),
or reduce soil atmospheric oxygen during decomposition
Herbicide bumdown and herbage removal were
shown to stimulate winter annual growth compared with
no herbicide bumdown in some, but not all years (Tables
1-3). Lang and Elmore (1995) concluded that herbicide
burndown of volunteer annual grasses was beneficial in
a wet year (1992), but not in a dry year (1993). There
was no difference between using paraquat or glyphosate.
In 1994-95, all plots were irrigated during establishment
and the ryegrass growing in the burndown plots yielded
more than the ryegrass sown into live annual sod
indicating that soil moisture can be conserved by using a
bumdown herbicide. However, yield response in
individual years was small (800 to 1000 lb/a) and may
not be economical compared with removing the herbage
with a final hay harvest or late summer grazing. Averaged
over three yr, there was no advantage to using a
burndown herbicide at the Starkville site (Table 1). No
advantage to using a bumdown herbicide was also not
found in the small plots at the Newton site (Table 2);
production pastures at Newton, however, have been
routinely sod-seeded into volunteer annual grasses
following herbicide burndown 30 d prior to planting
ryegrass in order to eliminate the herbage and conserve
Fall growth of summer annual grasses generally
diminishes, although in wet, warm years, growth may be
quite vigorous until first frost. Bermudagrass growth rate,
however, reduces rapidly in the fall after about 15
September even when well fertilized and irrigated
(Burton et al., 1988). Yields of winter annuals growing in
live or suppressed bermudagrass were equal (Table 3)
and this was in agreement with previous work (Lang et
al., 1992; Johnson and Lang, 1997). However, plants
sown in tilled plots yielded significantly more than those
sown into sod.
Total winter annual forage growth enhanced by
tillage has been found to be primarily due to enhanced fall
growth (Lang, 1989; Brock et al., 1992; Lang et al.,
1992; Lang and Elmore, 1995). Early fall enhanced
forage growth provides for early fall grazing; average
initial grazing date over four yr at the Brown Loam
Experiment Station in Raymond, MS was 23 November
for pastures seeded to ryegrass in a prepared seedbed, 4
December for those seeded NT into an annual sod, 17
December when seeded NT into an annual sod plus
paraquat, 3 or 5 January for bermudagrass pastures
seeded to ryegrass following light disking or paraquat,
and 24 January for bermudagrass pastures seeded NT
without herbicide suppression (Ingram et al., 1993). Sod-
seeding ryegrass into volunteer annual grasses provided
nearly the same economic return ($80.94/a) compared
with seeding into a prepared seedbed ($ 99.32/a). Using
paraquat for sod-suppression of either the annual or
perennial pasture reduced the economic return to $ 48.09
or $38.83, respectively (Ingram et al., 1993). They
concluded that "planting ryegrass into volunteer summer
annual grasses is a viable alternative to conventionally
tilled ryegrass pastures in Mississippi".
Fully prepared seedbeds may provide additional
forage growth, particularly early in the season, but soil
erosion may be high on some soil sites and year-round
utilization of the land resource may be reduced. There
may be numerous obstacles to sod-seeding winter
annuals, but most of these challenges can be overcome
with timely utilization of moderate tillage, herbage
removal prior to seeding, and limited herbage
suppression with burndown herbicides. Insect control has
not been fully investigated. A preliminary study at the
Starkville site indicated there was no benefit to applying
insecticides; all plots, including the control, had excellent
stands. Insect damage, seedling disease, soil to seed
contact, and soil moisture may contribute to some winter
annual sod-seeding failures; however, there remains an
unexplained suppression of sod-seeded winter annual
forages that occurs regardless of stand success, N rate,
soil moisture, sod type, or forage species.
Brock, B., J. Murphey, B. Johnson, D. J. Lang, and D.
Ingram. 1992. Overseeding winter annuals into
volunteer summer annual sod. pp. 34-37. In
MD. Mullen and B.N. Duck (eds.) Proceedings
1992 Southern Conservation Tillage Conference
for Sustainable Agriculture. Tennessee Agric.
Exp. Station Special Pub. 92-01.
Burton, G.W., J.E. Hook, J.L. Butler, and R.E. Hellwig.
1988. Effect of temperature, daylength, and
solar radiation on production of coastal
bermudagrass. Agron. J. 80:557-560.
Ingram, D., W. Addison, and R. Hardin. 1993. Influence
of conservation tillage on ryegrass and steer
performance, p. 57. In P.K. Bollich (ed.).
Proceedings 1993 Southern Conservation
Tillage Conference, Monroe, LA.
Johnson, B.B., and D.J. Lang. 1993. Winter Annuals
Grown in Conventional and Reduced Tillage
Systems Followed by Volunteer Summer
Annuals. 1993. In N.M. Cox and W.B.
McKinley (eds.). Livestock Day Report.
MAFES Info. Bull. 243:60.
Johnson, B. B., and D. J. Lang. 1994. Winter annuals
grown under conventional and reduced tillage
systems followed by volunteer summer annuals.
In J.W. Fuquay (ed.). Dairy Day Report 1994.
MAFES Info. Bull. 266:28.
Johnson, B.B., and D.J. Lang. 1997. Yield of cool season
forages grown under reduced tillage in a
Bermudagrass sod under various N rates in
1995-96. In 1996 Progress Report Central
Mississippi Research and Extension Center.
MAFES Info. Bull. 318:71.
Johnson, B. B., B. Brock, and D. Lang. 1991. Cool
Season Forages Under Conventional and
Reduced Tillage Conditions Planted in
Bermudagrass Sod. In 1990 Research Progress
Report Coastal Plains Branch. MAFES Info.
Johnson, B. B., W.A. Brock, and D. Lang. 1992.
Ryegrass Grown under Conventional and
Reduced Tillage Systems followed by
Volunteer Crabgrass and Brachiaria. 1992. In
R. B. Moore and J. W. Fuquay (eds.). Dairy Day
Report 1992. MAFES Info. Bull. 20:25.
Johnson, B. B., B. Brock, and D. Lang. 1992. Cool
Season Forages Under Conventional and
Reduced Tillage Conditions Planted in
Bermudagrass Sod. In R. B. Moore and J. W.
Fuquay (eds.). Dairy Day Report 1992.
MAFES Info. Bull. 220:17.
Johnson, B. B., B. Brock, and D. Lang. 1993. Cool
Season Forages Under Conventional and
Reduced Tillage Conditions Planted in
Bermudagrass Sod. In 1992 Research Progress
Report Coastal Plains Branch. MAFES Info.
Johnson, B.B., W.A. Brock, D. Lang. 1994. Yield of
cool season forages grown under reduced tillage
in a bermudagrass sod under various nitrogen
rates. In J.W. Fuquay (ed.). Dairy Day Report
1994. MAFES Info. Bull. 266:33.
Lang, D. J. 1989. Comparative effects of tillage on
winter annual forage production. pp. 62-64. In
Proceedings 1989 Southern Conservation
Tillage Conference. Special Bulletin 89-1,
Institute of Food and Agricultural Sciences,
University of Florida, Gainesville, FL.
Lang, D.J. 1993. Factors affecting the sod seeding of
winter forages. Proc. 49th Southern Pasture and
Forage Crops Improvement Conf. 49:59-63.
Lang, D., and R. Elmore. 1995. Effect of Bumdown
Herbicide, Tillage, and N Rate on Fall Growth
of Sod-Seeded Ryegrass. pp. 52- 54. In
W.L. Kingery and N. Buehring (eds.).
Proceedings 1995 Southern Tillage Conference
for Sustainable Agriculture. MAFES Special
Bulletin 88-7 Mississippi Agricultural and
Forestry Experiment Station, Mississippi State.
Lang, D. J., D. Ingram, B. Brock, and B. Johnson. 1992.
Establishment of winter forages into summer
annual or perennial grass sods. pp. 94-97. In
M.D. Mullen and B.N. Duck (eds.).
Proceedings. 1992 Southern Conservation
Tillage Conference for Sustainable Agriculture.
Tennessee Agric. Exp. Sta. Special Pub. 92-
Effect of Burndown Herbicide on Ryegrass
Sown in Annual Grasses
Experiment # 1, Starkville, MS
Errata Table 1 Lang etal., Page 63
Table 1. Effect of burndown herbicide on yield of ryegrass sown into volunteer annual
grasses (crabgrass and broadleaf signalgrass)at Starkville, Mississippi
Seedbed -------- Total Yield by Year -------------
Preparation 1992-93' 1993-942 1994-953 Three-Year Average
---------- lb dry matter per/a -------------
Burdown 4694 B 3218 B 5055 A 4322 B
Live Sod 3948 C 3323 B 4767 C 4021 B
Tilled4 7586 A 4243 B 4767 B 5532 A
LSD (0.05) 497 308 264 463
Means followed by the same letter within each column do not differ.
'Paraquat at 2 pts/a applied 11 Aug. 1992; planted 7 Oct. 1992; (Lang and Elmore, 1995).
2 Roundup at 2 qts/a applied 10 Aug. 1993; planted 24 Sept. 1993; (Lang and Elmore, 1995).
3Roundup at 2 qts/a applied 3 Aug. 1994; planted 16 Sept. 1994; 100 lbs N/a.
4 Tillage (roto-tilling) was initiated when herbicide was applied on bumdown plots
Table 2. Yield of ryegrass as affected by tillage, herbage removal, and burndown herbicide
sown into broadleaf signalgrass at Newton, Mississippi, 1994 to 1996.
Preparation 1994-1995 1995-1996 Two Year Average
-------------------- lb dry matter/a -----------
Deep Disk (DD) July 4319AB 5076 A 4698 A
Deep Disk August 4585 A 4388 BC 4487 AB
Light Disk July 4015 BC 4667 AB 4341 ABC
Light Disk August 3967 BCD 4433 ABC 4200 BC
Hay Cut September +DD 4303 AB 4216 BC 4260 BC
Hay Cut September + RU 3588 CD 3890 C 3739 D
Roundup (RU) September 3798 CD 4288 BC 4043 CD
Hay Cut September 3526 D 3911C 3719 D
LSD (0.05) 463 649 425
Means followed by the same letter within each column do not differ. 'Marshall' ryegrass was planted
the first week of October each year. Roundup at 1 qt/a was applied two to three weeks prior to planting.
Final hay harvest was also two to three wk prior to planting as was the deep disking following hay
harvest treatment. All plots received 65-65-65 at planting and an additional 34 lb N/a per harvest each yr.
Table 3. Yield of winter forages sown into bermudagrass sod as affected by tillage,
herbicide suppression, and subsequent effect on bermudagrass growth and
persistence at Newton, MS.
Seedbed --------- Three Year Average Total Yield ------ Final Stand of
Preparation Winter Forages Bermudagrass Bermudagrass
------------ lb dry matter/a ---------------- ---- % ----
No-Till (NT) 4068 AB 3826 A 74 A
NT +Roundup 3961 B 3093 B 63 AB
Single Disk 3956 B 2585 BC 33 B
Double Disk 4471 A 2154 C 27 B
LSD (0.05) 448 626 37
Means followed by the same letter within each column do not differ. Three-year average from
1989 to 1992. Data from Johnson et al., 1991; 1992; 1993. Roundup at 1 pt/a was applied in late
August each year. Tillage was done in late August and all plots were seeded by the first wk of October.
Winter forages were ryegrass, ryegrass + rye, and ryegrass + red clover. Means presented are the
average yield of the three forages.
Alternative Arkansas Rotations and Tillage Practices
C.R. Dillon, *T.C. Keisling, RD. Riggs, and L.R. Oliver
The objective of this study was to provide
agronomic, nematode, and economic analysis of
alternative production rotation systems for soybean
(Glycine max ) on an Arkansas silt loam.
Monocropped soybean and soybean double-cropped
with wheat (Triticum aestivum ) was included as well
as grain sorghum (Sorghum bicolor) under dryland
conditions in order to reduce soybean cyst nematode
(Heterodera glycines) populations. A total of seven
crop rotations and 11 treatments that included
alternative tillage conditions and wheat stubble
management practices were analyzed using data
from experiments conducted from 1980 to 1984 at
the Arkansas Cotton Branch Experiment Station on
a Loring-Calloway-Henry silt loam. Although crop
rotation was effective for nematode suppression,
yields for double-cropped soybeans were comparable
to soybean yields under monocropped, continuous
management practices. Economic results indicated
that average net returns of $137/a were highest for
the continuous double-cropped wheat-soybean
production management systems which combine the
conventional tillage method with burning of wheat
stubble. For the conditions analyzed and level of
soybean cyst nematode present, this research
provides evidence that control of the soybean cyst
nematode through rotation practices that utilize
grain sorghum is not economically efficient where
continuous double-cropped wheat-soybeans systems
can be incorporated.
Crop rotation has been recognized for years as
a primary strategy for the effective control of soilbome
diseases. With the removal of dibromochloropropene,
usually the most cost-effective nematicide in soybean
(Glycine max [L.] Merr.) production, the use of resistant
'C.R. Dillon, 'T.C. Keisling, 'RLD. Riggs, and 4L.R.
Oliver. 'Agri. Economics Dept., 'Plant Pathology Dept.,
4Agronomy Dept., University of Arkansas, Fayetteville,
AR, and 2Agronomy Dept, University of Arkansas at
Northeast Research and Extension Center, Keiser, AR.
Manuscript received 10 April 1997. Corresponding
soybean cultivars, coupled with crop rotation, is
seemingly the only remaining control strategy for the cyst
nematode (Heterodera glycines Ichinohe). Previous
research has indicated that non-host crops for one year in
the rotation dramatically decreased the nematode
population (Slack et al., 1981; Dabney et al., 1988).
Research conducted in Kentucky indicated that the
combination of no-till and leaving wheat (Triticum
aestivum L.) straw generally suppressed nematode
populations (Hershman and Bachi, 1995), whereas
Alabama evidence shows little effect (Edwards et al.,
1988). In the Mississippi Delta and Loessial Terraces
regions of Arkansas, several million acres of loess-
derived soils are very low in organic matter and are
subject to severe cyst nematode problems.
In these regions, nonirrigated silt loam soil not
cropped to cotton (Gossypium hirsutum L.) is almost
exclusively cropped to continuous soybean or double-
cropped wheat-soybean. The wheat residue usually is
burned. This practice of wheat straw burning has been
perceived by agronomists as an undesirable practice on
soils with very low organic matter (<0.8%) for as long as
it has been practiced. The objective of this study was to
examine the profit potential of alternative soybean
production rotation systems on an Arkansas silt loam
within a multidisciplinary agronomicc, pathologic, and
MATERIALS AND METHODS
As a multidisciplinary study, several
methodological aspects are discussed. Procedures for the
agronomic component, nematode assay, and economic
analysis are presented.
Experiments were conducted from 1980 to 1984
at the Arkansas Cotton Branch Experiment Station on a
Loring-Calloway-Henry silt loam. The initial soil test
values were 6.2 for soil pH with 0.6% organic matter and
64 lb P/a and 170 lb K/a.
The study included seven rotational cropping
systems composed of continuous soybean
(monocropped), wheat-soybean double-cropped, and five
biennial rotations of which two were single crops per
year and the remaining three were double-crop systems.
The exact cropping sequences are shown in Table 1.
Also defined in Table 1 are various cropping-system
designations. Additional cultural practices were imposed
on selected crop rotations. The continuous soybean and
wheat-soybean double-crop systems were grown under
both conventional tillage and no-till methods. The wheat-
soybean double-crop system also had residue
management treatments in that the wheat stover was
either burned or left on the surface. This plan resulted in
a total of four double-cropped wheat-soybean production
systems and two continuous soybean systems.
A total of 11 crop production systems were
arranged in a randomized complete block design with
three replications. Individual production system plots
were 13.7 ft wide x 100 ft long. Grain sorghum and
soybean were planted on 38 in. rows with a conventional
planter (John Deere 7100") equipped for no-till by using
cutting coulters, double disk openers, cast iron press
wheels and heavy down pressure springs while the wheat
was sown in 7.5-in. rows with a Crust Buster" no-till
drill. Wheat residue was burned in all cases where the
crop production system is not otherwise specified.
The study area was planted to soybean in the
summer of 1980. The study began with wheat planted
that fall and summer crops in the spring of 1981. Yields
were determined by harvesting the two middle rows in
each plot for both grain sorghum (Sorghum bicolor [L.]
Moench) and soybean and a 60-in.-wide swath in the
middle of the wheat plots. Grain yields were adjusted to
14.0, 13.0, and 13.0% moisture for grain sorghum,
soybean, and wheat, respectively. The specific features
of each production system were commensurate with
commercial production practices used in the area.
Every plot was sampled each fall for soybean
cyst nematode population density determinations. Soil
samples from the 0 to 4 in. depth were taken from the
seedling row with a soil probe to generate 20 samples per
plot. Second-stage juveniles of H. glycines were
extracted (Southey, 1986), counted, and analyzed
statistically using a square root transformation.
Economic analysis was conducted using
enterprise budgeting techniques. Budgets were compiled
on each cropping system annually by using the
Mississippi State Budget Generator computer program
(Spurlock, 1992). In order to remove the effects of
market fluctuations and focus upon production economic
issues, crop prices were based on a 10-yr average (1985-
1994) for each crop (Anon., 1995). These prices were
$5.92/bu for soybeans, $3.12/bu for wheat, and $1.95/bu
for grain sorghum. Recent data were used to reflect
current conditions. Total income was calculated by
multiplying yield and average crop price. Direct
expenses were calculated using the average prices paid
for seed, chemicals, fertilizer, custom work, labor,
repairs, maintenance, fuel, and interest on operating
capital. Input requirements were those actually used for
seed, chemicals, fertilizer, etc., with standard American
Society of Agricultural Engineers (ASAE) machinery
costs calculations for the remainder using recent ASAE
coefficients. Recent input prices for Arkansas (Anon.,
1994) were also used. Fixed expenses include
depreciation, insurance, property taxes, and interest on
capital invested associated with tractors, combines, and
other field equipment. Total expenses included both the
direct and fixed expenses. Net returns are considered the
difference between total income and total expenses.
Average net returns are calculated over the 4-yr period.
Gross income, total expenses, and net returns for the
double-crop rotations include the total income, expenses,
and returns for both crops produced in each system. No
charge was issued for land, risk, overhead labor, other
overhead, crop insurance, real estate taxes, or
RESULTS AND DISCUSSION
Although economic considerations are a primary
motivation of production management decision-making,
knowledge of the underlying production processes is
crucial to the realization of economic objectives.
Consequently, results are presented, in turn, for three
components that affect performance: agronomic,
pathologic (nematode), and economic.
Grain yields for the study generally follow
expectations for the crops and cultivars used in the study
area without irrigation (Table 2). These particular crop
rotations were selected for the alternation of host crop for
the management of soilborne plant pathogens, a weed
spectrum easily controlled by available herbicides, and
economic potential. Other production practices were
included to reduce mechanical inputs (no-till) or to retain
The nematode analyses indicated that leaving
wheat residue or burning it did not significantly influence
the associated nematode population which averaged 700
and 509 juveniles per pt of soil for wheat residue burned
or unburned, respectively. This reduction in nematodes
from leaving wheat straw, while not significant, tends to
agree with that reported by Hershman and Bachi (1995).
Crop rotations used in this study were of two
types: 1) those recommended for nematode suppression
that contain a year of non-host crop and 2) those not
recommended for nematode suppression that contain host
crops planted every year. Rotations were, therefore,
classed according to these two schemes. The crop
rotation x year interaction was highly significant (P=0.01)
and is shown graphically in Figure 1. Essentially, in the
fall following a year of non-host crop, the nematode
populations were suppressed to a very low level as
compared to rotations containing a host crop every year.
This finding illustrates the effectiveness of crop rotation
for nematode suppression.
The tillage effect on nematode populations was
found to be highly significant (P=0.01) and to be
independent of crop rotation and year. The data are
presented only for continuous single and double-crop
soybean (Figure 1). Both rotations had host plants
seeded each year. However, the no-till resulted in
substantially fewer nematodes than the tilled systems.
The no-till production system suppressed the nematodes
as well as non-host crop rotation. This result suggests
that no-till could well be considered as an alternative to
crop rotation for nematode suppression. However, on
some soils, the reduction in nematode population density
made during a no-till crop may not be sufficient to
prevent damage the next year if a susceptible cultivar is
As expected, net returns varied across years and
treatments (Table 3). Over the entire 4 yr of the study,
average net returns/a ranged from a high of $136.99 for
conventionally produced double-cropped wheat-soybean
to a low of $39.44 for no-till continuous soybean (Table
4). Of the crop rotation systems, the wheat-soybean
continuous double-cropped systems, regardless of tillage
practice and stubble management, produced the largest
net returns. The least favorable of these four was for
soybean no-tilled into wheat residue. At the time of this
study, the technology was not available to make this
treatment yield as it should (Keisling et al., 1994).
Therefore, the net returns reported for continuous double-
cropped wheat-soybean with wheat residue left and
soybean no-tilled into the wheat straw will be lower than
what can be currently expected.
The next most profitable systems were
continuous double-cropped wheat-soybean-monocropped
soybean, monocropped grain sorghum-soybean, and
double-cropped wheat-grain sorghum-monocropped
soybean. These crops were about two-thirds as profitable
as the most profitable system. The least profitable
rotation was continuous no-till soybean. Net returns for
wheat-summer fallow-monocropped soybean were the
next lowest. Net returns for the least profitable
continuous no-till soybeans were less than one third of the
net returns achieved by the most profitable group.
In order to expand the potential for application
of the research results to a more diverse set of conditions
and address the limitation of the study related to the yield
data used, sensitivity analysis was conducted.
Specifically, given the wide range of production
management abilities, soil potential, and different
resources and conditions, yields understandably varied
dramatically. This variation in yield obviously has a
substantial impact on the net returns that a producer
receives. Furthermore, yields have been impacted by
changes in technology, cultivar availability, and
management information. Consequently, average net
returns for selected treatments are calculated under a
range of soybean yields and other crop yields. The yield
sensitivity analysis focused upon four treatments:
conventional, continuous GS/S; conventional, continuous
soybeans; no-till continuous soybeans; and conventional
continuous, double-cropped wheat-soybeans with burned
wheat stubble. In all cases, soybean yields were varied in
10-bu increments from 10 to 40 bu/a. Grain sorghum
yield was varied in 10-bu increments from 60 to 80 bu/a
and wheat yield was varied in 10-bu increments from 30
to 50 bu/a. The results are presented in Table 5.
Notably, all double-cropped wheat-soybean yield levels
examined still earned positive net returns and, with a 60
bu/a sorghum yield exception on the GS/S rotation, all
20 bu/a soybean yield levels were sufficient to result in
positive net returns for the remaining treatments and yield
In conclusion, the results of the study emphasize
the advantage of conducting research within a
multidisciplinary framework, given the complicated
environment which faces farm managers in their
production management decisionmaking. While
inclusion of grain sorghum in the rotation was effective in
reducing soybean cyst nematode populations, the
agronomic production function was such that soybean
yields under continuous double-cropped wheat-soybean
production practices were comparable to continuous
monocropped soybeans. Furthermore, the additional net
returns achieved from wheat complemented the
continuous double-cropped wheat-soybean production
strategy enough to compensate for the lower soybean
yields compared to the grain sorghum rotations.
Although control of soybean cyst nematode is essential to
good production management, one should consider the
economic impact of switching to less profitable
Anonymous. 1994. Estimating 1995 production costs in
Arkansas. Ext. Tech. Bull. Nos. 206-249,
Arkansas Cooperative Extension Service,
University of Arkansas, Fayetteville, AR..
Anonymous. 1995. Arkansas Agricultural Statistics
1994. Arkansas Agricultural Statistics Service.
Arkansas Agr. Exp. Sta., Report Series 330,
University of Arkansas, Fayetteville, AR..
Dabney, S.M., E.C. McGawley, D.J. Boethel, and D.A.
Berger. 1988. Short-term crop rotation systems
for soybean production. Agron. J. 80:197-204.
Edwards, J.H., D.L. Thurlow, and J.T. Eason. 1988.
Influence of tillage and crop rotation on yields
of corn, soybean, and wheat Agron. J. 78:875-
Hershman, D.E., and P.R. Bachi. 1995. Effect of wheat
residue and tillage on Heterodera glycines and
yield ofdoublecrop soybean in Kentucky. Plant
Keisling, T.C., N.W. Buehring, L.O. Ashlock, G.A.
Jones, J.D. Wadick, and J.E. Askew. 1994.
Differential soybean varietal response to no-till
planting in wheat straw. pp. 89-94. In P.J.
Bauer and W.J. Busscher (eds.). Proc. 1994
Southern Conservation Tillage Conference for
Sustainable Agriculture. USDA-ARS, Coastal
Plains Soil, Water, and Plant Research Center,
Sanford, J.O. 1982. Straw and tillage management
practices in soybean-wheat double-cropping.
Agron. J. 74:1032-1035.
Sanford, J.O., B.R. Eddleman, S.R. Spurlock, and
J.E.Hairston. 1986. Evaluating ten cropping
alternatives for the midsouth. Agron. J.
Slack, D.A., R.D. Riggs, and M.L. Hamblen. 1981.
Nematode control in Arkansas; rotation and
population dynamics of soybean cyst and other
nematodes. Ark. Agric. Exp. Sta. Rept. Ser.
263, Univ. of Arkansas, Fayetteville, AR.
Southey, J.F. 1986. Laboratory methods for work with
plant and soil nematodes. Her Majesty's
Stationery Office, London.
Spurlock, R. 1992. Mississippi State University Budget
Generator. Mississippi State Univ. Agric. Exp.
Stn. Tech. Bull. No. 52, Mississippi State, MS.
Vanderlip, R.L., and H.E. Reeves. 1972. Growth stages
of sorghum. Agron. J. 64: 13-16.
Table 1. Cropping Sequences and Seedbed Preparation for Eleven Crop Production Systems from 1981 to 1984
Wheat 1980 1981 1982 1983 1984
Rotationt Tillaget Mgmt. Winter Summer Winter Summer Winter Summer Winter Summer
GS/S Conv. GS S GS S
S/S Conv. S S S
S/S No-till -S S S S
W-F/S Conv. Bum W -- S W -- S
W-GS/S Conv. Bum W GS S W GS S
W-GS/W-S No-till Bum W GS W S W GS W S
W-S/S Conv. Bum W S S W S S
W-S/W-S Conv. Bum W S W S W S W S
W-S/W-S No-Till Bum W S W S W S W S
W-S/W-S Conv. Leave W S W S W S W S
W-S/W-S No-till Leave W S W S W S W S
tYearly cropping rotations are divided by and individual crops harvested same year are divided by '-', crops are shown as 'GS' for grain sorghum, 'S' for soybean, 'W'
for wheat, and 'F' for fallow.
*Mgmt refers to management (Bum indicates wheat stubble is burned, Leave indicates the stubble is left unbumed on the surface).
Table 2. Grain Yield for the Eleven Crop Sequences
Crop Wheat Stubble Year
Rotation Tillage Mgmt.t Crop 1981 1982 1983 1984 Avg.
------------------------------------------ bu/a --------------a---------------------------
GS/S Conv. --- GS 86.0 --- 107.1 --- 96.6
GS/S Cony. --- S --- 40.8 --- 36.8 38.8
S/S Cony. --- S 28.7 31.2 17.1 35.4 28.1
S/S No-Till --- S 34.6 20.2 10.7 31.2 24.2
W-F/S Cony. Bum W 34.0 --- 38.6 --- 36.3
W-F/S Cony. Bum S --- 34.7 --- 34.6 34.6
W-GS/S Conv. Bum W 34.0 --- 40.6 -- 37.3
W-GS/S Cony. Bum GS 62.3 --- 62.3 --- 62.3
W-GS/S Cony. Bum S --- 36.7 --- 36.9 36.8
W-GS-/W-S No-Till Bum W 34.0 28.0 40.1 32.3 33.6
W-GS/W-S No-Till Bur GS 36.0 --- 35.5 --- 35.8
W-GS/W-S No-Till Bur S --- 28.7 --- 33.9 31.3
W-S/S Cony. Bum W 34.0 --- 40.1 --- 37.1
W-S/S Conv. Bum S 27.1 32.7 16.4 39.0 28.8
W-S/W-S Cony. Bum W 34.0 34.7 37.6 42.1 37.1
W-S/W-S Cony. Bum S 34.6 30.3 19.4 33.9 29.5
W-S/W-S No-Till Bur W 34.0 32.0 38.6 43.9 37.1
W-S/W-S No-Till Bur S 35.3 31.2 19.0 35.4 30.2
W-S/W-S Cony. Leave W 34.0 31.4 35.7 34.1 33.8
W-S/W-S Cony. Leave S 33.1 31.0 16.8 36.5 29.4
W-S/W-S No-Till Leave W 34.0 34.0 37.1 23.7 32.2
W-S/W-S No-Till Leave S 39.5 29.4 19.0 26.6 28.6
t Yearly cropping rotations are divided by '/' and individual crops harvested same year divided by'-', crops are shown as 'GS' for grain sorghum, 'S' for soybean,
'W' for wheat and 'F' for fallow.
tMgmt refers to management (Bum indicates wheat stubble is burned, Leave indicates the stubble is left on the surface).
IMeasured plots yields of 16 bu/a were based on experiment station average on 300 a. Small plots of early grain sorghum were heavily damaged by birds.
Table 3. Total Income (TINC), total Expenses (TEXP) and Net ReturnsAbove Expenses (NRET) for the Eleven Crop Systems
tYearly cropping rotations are divided by '/' and individual crops harvested same year are divided by '-', crops are shown as 'GS' for grain sorghum, 'S' for soybean,
'W' for wheat and 'F' for fallow.
tMgmt refers to management (Bur indicates wheat stubble is burned, Leave indicates the stubble is left unbumed on the surface.
Table 4. Averages for Total Income (TINC), Total Expenses (TEXP) and Net Returns Above Expenses (NRET) for the Eleven Crop Systems
Average of 1981 through 1984
Crop Rotationt Tillage Stubble Mgmt.t TINC TEXP NRET
GS/S Conv. -- 209.04 122.46 86.58
S/S Conv. --- 166.44 100.26 66.19
S/S No-till --- 143.04 103.61 39.44
W-F/S Conv. Bur 159.15 100.14 59.01
W-GS/S Conv. Bum 227.89 151.13 76.76
W-GS/W-S No-till Bur 232.36 162.59 69.77
W-S/S Cony. Bur 228.29 134.81 93.49
W-S/W-S Cony. Bum 290.60 153.62 136.99
W-S/W-S No-till Burn 294.76 161.50 133.26
W-S/W-S Conv. Leave 279.28 159.17 126.35
W-S/W-S No-till Leave 269.88 165.70 104.18
tYearly cropping rotations are divided by 7 and individual crops harvested same year are divided by '-', crops are shown as 'GS' for grain sorghum, 'S' for soybean, 'W'
for wheat and 'F' for fallow.
IMgmt refers to management (Bur indicates wheat stubble is burned, Leave indicates the stubble is left unburned on the surface).
Table 5. Average Net Returns' ($/a) Sensitivity Analysis of Yield Effects for Selected Treatments
Nonsoybean Soybean Yield
Rotationt Tillage Crop Yield 10 20 30 40
GS/S Conv. GS 60 -29.42 -0.58 28.27 57.11
GS/S Cony. GS 70 -20.43 8.42 37.27 66.11
GS/S Cony. GS 80 -11.43 17.42 46.26 75.10
S/S Cony. NA NA -39.37 18.32 76.01 133.70
S/S No-till NA NA -41.29 16.41 74.10 131.78
W/St Cony. W 30 3.24 60.93 118.62 176.31
W/S* Cony. W 40 32.89 90.58 148.26 205.95
W/St Cony. W 50 62.53 120.22 177.91 235.60
tYearly cropping rotations are divided by '/ and individual crops harvested same year are divided by'-', crops are shown as 'GS' for grain sorghum, 'S' for soybean, 'W'
for wheat and 'F' for fallow.
IThe wheat stubble was burned.
S 0001981 1982 1983 1984 1985 1986"
Note: Recommended includes grain sorghum in 81, 83 and 85.
Not recommended exc ..grain
@ Not Recommended Recommended Tilled No-Till
S1981 1982 1983 1984 1985 1986
Note: Recommended includes grain sorghum in 81, 83 and 85.
Not recommended excludes grain sorghum.
Methods for Managing Nematodes in
*R McSorley and R. N. Gallaher
The efficacy of tillage, yard-waste compost
amendment, and crop rotation for management of
plant-parasitic nematodes were examined in a
number offield tests in north-central Florida. Tillage
practices affected (P<0.10) nematode population
densities in only a few cases. Yard-waste compost
had little effect on nematode numbers in the first
season following application, but there was evidence
of long-term effects on some nematodes. Crop
rotation was effective in reducing nematode
population densities in many tests. Rotation with
velvetbean (Mucuna deeringiana) was effective in
reducing numbers of Meloidogyne incognita (in 7 of
7 tests), Criconemella spp. (5 of 7 tests), and
Pratylenchus spp. (4 of 7 tests). Velvetbean and
certain cultivars of cowpea (Vigna unguiculata) and
sorghum (Sorghum bicolor) were particularly
effective against M. incognita, the key nematode pest
in many cropping systems in the region.
A number of non-chemical methods are
available for managing plant-parasitic nematodes and
reducing their population levels in sustainable
agricultural systems (McSorley, 1994; 1996; Trivedi and
Barker, 1986). These include use of resistant cultivars,
crop rotation and cover crops, fallow, flooding, tillage,
soil solarization, organic amendments, destruction of
weeds and crop residues, and other practices (McSorley,
1996; Trivedi and Barker, 1986). The design of
cropping systems and crop rotation schemes using
nematode-resistant crops and cultivars has been
particularly important in nematode management
(McSorley, 1996; McSorley and Gallaher, 1992b;
Trivedi and Barker, 1986).
In north-central Florida, a number of
experiments have been conducted to examine the effects
of tillage (McSorley and Gallaher, 1993a; 1994a,b),
'R. McSorley and 2R. N. Gallaher. 'Department Of
Entomology and Nematology and 'Agronomy
Department, University of Florida, Gainesville, FL.
Manuscript received 24 March 1997. Corresponding
organic amendments (McSorley and Gallaher, 1995a;
1996a), and crop rotation (McSorley and Gallaher, 1991;
1992a; 1993b) on plant-parasitic nematodes. The
purpose of this paper is to review the results from a large
number of tests to assess the relative utility of tillage,
organic amendments, and crop rotations for nematode
MATERIALS AND METHODS
From 1990 to 1995, a variety of tests were
conducted evaluating effects of tillage, organic
amendments, or crop rotation on population densities of
plant-parasitic nematodes in soil. All tests were
conducted in Alachua and Marion counties in north-
central Florida, on sandy soils consisting of 90 to 94%
sand, 2 to 5% silt, and 2 to 6% clay. Treatments were
imposed on small plots replicated in split-plot or
randomized complete block designs. A variety of crops
were examined in spring or summer experiments. Soil
samples for nematode analysis were collected at the time
of planting and harvest of each crop. Nematodes were
extracted from soil using a sieving and centrifugation
technique (Jenkins, 1964) and counted under a
microscope. Nematode count data were subjected to
analysis of variance followed by Duncan's multiple range
test to determine whether significant (at Ps0.05 or
P 0.10) treatment effects had occurred.
Tillage effects were evaluated in tests
comparing conventional and no-till treatments in the
management of tropical corn (Zea mays) cultivars during
the summer. A total of eight different tests were
conducted. Of these, five tests involved corn at different
sites following various cover crops or N regimes
(McSorley and Gallaher, 1994a). Three other tests were
conducted in another site, but in three different years
(McSorley and Gallaher, 1993a; 1994b).
Organic amendment effects were evaluated in
tests involving treatments with 269 mt/ha of yard waste
composts with C:N ratios of 35:1 to 46:1. The three
treatments involved in each test were: compost applied
to the soil surface as a mulch, compost incorporated into
the soil by rototilling, and an unamended control. Ten
tests involved evaluation of nematode numbers in the first
season after compost application on field corn at two sites
(McSorley and Gallaher, 1996a), and on four different
vegetable crops (sweet corn, cowpea [Vigna
unguiculata], squash [Cucurbita pepo], okra [Hibiscus
esculentus]) at two sites each (McSorley and Gallaher,
1995a). In two other tests, nematode population densities
on field corn were evaluated at two sites in the third year
following compost amendment in each of the previous
years (McSorley and Gallaher, 1996a).
Rotation effects were evaluated at seven
different sites in which nematode numbers following four
different summer rotation crops were compared with
nematode numbers following tropical corn cv. Pioneer
3098 (McSorley and Gallaher, 1992a). The four rotation
crops evaluated in each test were: soybean (Glycine max
cv. Howard), velvetbean (Mucuna deeringiana), cowpea
cv. California Blackeye #5, and sorghum (Sorghum
bicolor cv. Asgrow Chaparral). Nine addition
comparisons were made between nematode numbers
following a summer cover crop of tropical corn cv.
Pioneer X304C and sorghum cultivars DeKalb FS25E or
DeKalb BR64 or sorghum-sudangrass (S. bicolor x S.
sudanense) cv. DeKalb SX-17 (McSorley and Gallaher,
RESULTS AND DISCUSSION
Plant-parasitic nematodes commonly found in
the study sites included ring nematodes (Criconemella
spp. = Criconemoides spp., primarily C. ornata), the
root-knot nematode (Meloidogyne incognita), the stubby-
root nematode (Paratrichodorus minor), and lesion
nematodes (Pratylenchus spp., primarily P. scribneri).
Meloidogyne incognita is considered the key nematode
pest in this system (McSorley and Gallaher, 1992b).
Nematodes numbers did not differ much
between conventional and no-till treatments (Table 1).
At Ps0.05, only five significant differences were
observed, while at Ps0.10, eight such differences
occurred. In some of these instances, nematode numbers
were greater under no-till treatment, while in other cases,
numbers were greater following conventional tillage
(McSorley and Gallaher, 1993a). There is some evidence
that higher soil populations of Pratylenchus scribneri
result from conventional tillage (McSorley and Gallaher,
In the first season following application, yard-
waste compost was rather ineffective in reducing
numbers of plant-parasitic nematodes (Table 2).
Although in one test numbers of M. incognita were
reduced by mulch, in one other case M. incognita
numbers were greater in mulched plots than in
unamended control plots, and in another test M. incognita
numbers were greater in plots with incorporated compost
than in unamended plots (McSorley and Gallaher,
1995a). There was evidence that compost was more
effective against nematodes after a longer period of time,
as shown in tests which had received compost treatments
for three years (Table 3). However, even after this length
of time, there were no significant effects of compost on
M. incognita, the most serious nematode pest present in
Several rotation crops were effective in
lowering nematode numbers compared to levels found on
tropical corn (Table 4). Several different crops were
effective against M. incognita and Criconemella spp.,
and velvetbean was an effective rotation crop against the
widest range of nematodes. Velvetbean and the cowpea
cultivar used here reduced levels ofM. incognita in all
seven tests. Compared to population levels on corn,
reductions ranged from 37.4% to 98.6% following
cowpea, and from 70.6% to 99.9% following velvetbean.
The average ( standard deviation) reduction following
velvetbean was 91.0% (12.8).
In the nine comparisons of tropical corn and
various sorghum cultivars, numbers of M. incognita
following sorghum were reduced from those following
corn in 9/9 cases (data not shown). Reductions ranged
from 96.7% to 100%, with a mean ( standard deviation)
of 98.4% (1.06). Note that the sorghum cultivars used
inthese tests (McSorley and Gallaher, 1991; 1993b) are
different from the rather ineffective cultivar used in the
seven tests presented in Table 4 (McSorley and Gallaher,
In the cropping systems of north-central Florida,
it is evident that crop rotation is much more effective than
tillage or yard-waste compost amendment for
management of plant-parasitic nematodes, especiallyM.
incognita. For yard-waste compost application, the
principal benefit against nematodes may not be any
reduction of numbers, but the improvement of crop
tolerance to nematodes (McSorley and Gallaher, 1996b).
A number of summer and winter rotation crops can be
effective in reducing nematode numbers in this region
(McSorley, 1994; 1996; McSorley and Gallaher, 1991;
1992a,b; 1993a,b). However, with these crops, cultivar
choice can be critical, particularly with sorghum
(McSorley and Gallaher, 1991; 1992a; 1993b) and
cowpea (Gallaher and McSorley, 1993). Future research
is needed to identify candidate crops and cultivars
effective in rotations in Florida and other regions.
Gallaher, R. N., and R. McSorley. 1993. Population
densities of Meloidogyne incognita and other
nematodes following seven cultivars of cowpea.
Jenkins, W. R. 1964. A rapid centrifugal-flotation
technique for separating nematodes from
soil. Plant Dis. Reptr. 48:692.
McSorley, R.1994. Nematode management in
sustainable agriculture. pp. 517-522. In K.
L. Campbell, W. D. Graham, and A. B.
Bottcher (eds.). Environmentally Sound
Agriculture, Proceedings of the Second
Conference. Amer. Soc. Agric. Eng., St.
McSorley, R. 1996. Cultural control of plant-parasitic
nematodes. pp. 149-163. In D. Rosen, F. D.
Bennett, and J. L. Capinera (eds.). Pest
Management in the Subtropics. Intercept
Limited, Andover, UK.
McSorley, R., and R. N. Gallaher. 1991. Nematode
population -changes and forage yields of
six corn and sorghum cultivars. Suppl. J.
McSorley, R, and R N. Gallaher. 1992a. Comparison of
nematode population densities on six summer
crops at seven sites in north Florida. Suppl. J.
McSorley, R., and R. N. Gallaher. 1992b Managing
plant-parasitic nematodes in crop sequences.
Soil Crop Sci. Florida Proc. 51:42-45.
McSorley, R., and R. N. Gallaher. 1993a. Effect of
crop rotation and tillage on nematode
densities in tropical corn. Suppl. J. Nematol.
McSorley, R., and R. N. Gallaher. 1993b. Population
densities of root-knot nematodes following
corn and sorghum in cropping systems, pp. 26-
29. In P. K. Bollich (ed.). Proceedings of the
1993 Southern Conservation Tillage Conference
for Sustainable Agriculture. Louisiana
Agric. Expt. Sta. Ms. No. 93-86-7122,
McSorley, R., and R. N. Gallaher. 1994a. Effect of
tillage and crop residuemanagement on
nematode densities on corn. Suppl. J.
McSorley, R., and R. N. Gallaher. 1994b. Effect of
long-term rotation and tillage programs on
plant-parasitic nematodes. pp. 23-26. In
P. J. Bauer and W. J. Busscher (eds.).
Proceedings of the 1994 Southern Conservation
Tillage Conference for Sustainable Agriculture.
USDA-ARS Coastal Plain Soil, Water and
Plant Research Center, Florence, SC.
McSorley, R., and R. N. Gallaher. 1995a. Effect of
yard waste compost on plant-parasitic
nematode densities in vegetable crops.
Suppl. J. Nematol. 27:545-549.
McSorley, R., and R. N. Gallaher. 1995b. Effect of
tillage and liming on nematode
populations. pp. 23-25. In W. L. Kingery
and N. Buehring (eds.). Proceedings of
the 1995 Southern Conservation Tillage
Conference for Sustainable Agriculture.
Mississippi State University. Mississippi
McSorley, R., and R. N. Gallaher. 1996a. Effect of
yard waste compost on nematode densities and
maize yield. Suppl. J. Nematol. 28:655-660.
McSorley, R., and R. N. Gallaher. 1996b. Effect of
yard waste compost on crop tolerance to
root-knot nematodes. pp. 119-123. In
Proceedings of the 19th Annual Southern
Conservation Tillage Conference for
Sustainable Agriculture. Special Publication
96-07, University of Tennessee, West
Tennessee Experiment Station, Jackson, TN.
Trivedi, P. C., and K. R. Barker. 1986. Management of
nematodes by cultural practices. Nematropica
Table 1. Number of tests in which significant (at Ps0.05 or Ps0.10) differences between conventional and no-till
treatments were observed in nematode numbers measured at planting or harvest of corn.
Number of tests
Differences at PR0.05 Differences at Ps0.10
Planting Harvest Planting Harvest
Criconemella spp. 0nt 0/8 0/7 0/8
Meloidogyne incognita 0/7 0/8 0/7 0/8
Paratrichodorus minor 2/7 0/8 2/7 1/8
Pratylenchus spp. 1/7 2/8 2/7 3/8
tNo. of tests with differences/Total no. of tests observed.
Table 2. Number of tests in which a significant (at P-0.10) reduction in nematode numbers measured at planting
or harvest of corn and vegetable crops was obtained by a yard-waste compost (incorporated or mulch) treatment
in the first season after compost application.
Numbers of tests
Nematode Planting Harvest Planting Harvest
Criconemella spp. 0/10 1/10 0/10 1/10
Meloidogyne incognita 0/10 0/10 0/10 1/10
Paratrichodorus minor 0/10 1/10 0/10 0/10
Pratylenchus spp. 0/10 0/10 0/10 0/10
INo. of tests with significant reductions compared to control/Total no. of tests observed.
Table 3. Number of tests in which a significant (at PR0.10) reduction in nematode numbers measured at planting
and harvest of corn was obtained by a yard-waste compost (incorporated or mulch) treatment, in plots which had
received compost treatments for three years.
Number of tests
Nematode Planting Harvest Planting Harvest
Criconemella spp. 1/2t 2/2 1/2 2/2
Meloidogyne incognita 0/2 0/2 0/2 0/2
Paratrichodorus minor 1/2 1/2 1/2 1/2
Pratylenchus spp. 2/2 0/2 2/2 0/2
'No. of tests with significant reductions compared to control/Total no. of tests observed.
Table 4. Number of tests in which nematode numbers following a summer cover crop were significantly lower (at
P<0.05) than numbers following tropical corn.
Number of tests by cover crop
Nematode Soybean Velvetbean Cowpea Sorghum
Criconemella spp. 4/7 5/7 2/7 0/7
Meloidogyne incognita 4/7 7/7 7/7 2/7
Paratrichodorus minor 1/ 1/7 1/7 0/7
Pratylenchus spp. 0/7 4/7 1/7 0/7
1No. of tests with significant reductions compared to corn/Total no. of tests observed.
Cover Crop and Herbicide Burndown Effects
on No-Till, Water-Seeded Rice
The majority of no-till, water-seeded rice
(Oryza sativa) in southwest Louisiana is planted into
native vegetation grown over the winter months prior
to spring planting. Cover crops that produce
uniform growth, do not compete with the following
rice crop during the critical stand establishment
stage, and are easily controlled by burndown
herbicides could provide a more desirable seedbed in
which to establish rice. A study was conducted in
1995 and 1996 to evaluate various cover crop and
preplant vegetation management combinations for
their potential use in no-till rice production. Nine
cover crops included both clover and grass species,
and four preplant vegetation management strategies
included three burndown herbicides and a no-
herbicide treatment. Significant interactions
occurred between preplant vegetation management
and cover crops for days to 50% heading, plant
height, and grain yield. Maturity was delayed in
most cover crops when no herbicide was used to
control preplant vegetation and was most
pronounced in the clover cover crops both years.
Maturity was significantly delayed in a ryegrass
(Lolium muliflorum) cover crop in 1995 and in both
berseem clover (Trifolium alexandrinum) and
ryegrass cover crops in 1996, regardless of preplant
vegetation management treatment. Influence of
cover crop and preplant vegetation management on
plant height was less dramatic. Plant height
reductions in 1995 generally occurred when no
burndown herbicide was used to control preplant
vegetation. In 1996, plant height reductions were
also caused by some cover crops. Grain yields were
reduced in most cover crop/no-herbicide
combinations each year. Rice grain yields were also
reduced with berseem clover and ryegrass cover
crops, regardless of preplant vegetation management
treatments each year. When burndown herbicides
were used to control preplant vegetation, most cover
crops behaved similarly to native vegetation. When
P.K. Bollich. Louisiana State University Agricultural
Center, Rice Research Station, Crowley, LA. Manuscript
received 27 March 1997.
no burndown herbicides were used, only spring
triticale (Triicosecale) and wheat (Triticum aestivum)
were suitable alternatives to native vegetation.
Regardless of preplant vegetation management,
berseem clover and ryegrass are the least desirable
cover crops to use for no-till rice establishment.
Rice (Oryza sativa L.) production in Louisiana
with reduced tillage systems has steadily increased since
1990. Approximately 15% of the state's rice acreage is
currently devoted to conservation tillage practices (J.K.
Saichuk, 1997, personal communication). A small
percentage is rice seeded directly into crop residue from
the previous season. The most popular practice,
however, is to prepare a seedbed in the fall, allow it to
revegetate with winter weeds, use a chemical burndown
in the spring two to four wk preplant, and either water
seed or drill seed. The mild winters in Louisiana are very
conducive to establishment of native vegetation in most
There has been little interest in utilizing a
planted cover crop for no-till rice production. In a study
conducted by Eastman (1986), crimson clover (Trifolium
incarnatum L.) and subterranean clover (Trifolium
subterraneam L.) were evaluated for their potential as a
cover crop for rice. Stand densities were reduced four wk
after rice establishment, but rice grain yields were
affected at only one location in one yr. This study was
conducted in a drill-seeded cultural system. The potential
for stand reductions in rice no-tilled into preplant
vegetation is greater in a water-seeded system (Bollich,
A disadvantage of native vegetation as a cover
crop is that its composition varies due to previous tillage
practices, soil area differences, and whether the rice field
remains drained or flooded over the winter. Successful
termination of preplant vegetation is dependent upon the
ability of a burdown herbicide to effectively control a
wide array of weed species. Since the composition of
native vegetation can range from easily controlled, small
winter annuals to more difficult to control perennial
weeds, complete control of all preplant vegetation is
seldom achieved. A planted cover crop with modest
winter growth potential that is easily controlled with a
preplant burndown herbicide should provide a more
uniform and problem-free seedbed into which no-till rice
can be planted.
The objectives of this study were to: 1) evaluate
clover and grass cover crops as alternatives to native
vegetation in a water-seeded, no-till rice system, and 2)
evaluate three burndown herbicides and a no-herbicide
control for preplant vegetation management.
MATERIALS AND METHODS
An experiment was conducted at the South Unit
of the Rice Research Station, Crowley, LA, in 1995-1996
to evaluate the effects of cover crops and burndown
herbicides on no-till, water-seeded rice. Approximately
45 lb/a of P20, and K2O were incorporated in the fall
prior to cover crop establishment.
Various grasses and clovers were evaluated to
determine their potential as alternatives to a native
vegetation cover crop. In 1995, berseem clover
(Trifolium alexandrinum L.), ladino clover (Trifolium
repens L.), red clover (Trifolium pratense L.), rose
clover (Trifolium hirtum All.), yellow sweetclover
(Melilotus officianalis [L.] Lam.), cereal rye (Secale
cereale L.), ryegrass (Lolium multiflorum Lam.), and
wheat (Triticum aestivum L.) were evaluated. In 1996,
ladino clover, rose clover, yellow sweetclover, and cereal
rye were replaced with white clover (Trifolium repens
L.), 'Morey' wheat (a very short season wheat variety),
spring triticale (Tritosecale Wittm.), and buckwheat
(Agropyron repens). Buckwheat is a cool-season forage
sensitive to low temperature, and 6-wk after planting, an
early frost terminated its stand. It was replaced with a
multiple bumdown treatment (repeated herbicide
applications to maintain a vegetation-free seedbed).
Three burndown herbicides and a no-herbicide control
were evaluated in combination with each cover crop.
Roundup (glyphosate), Liberty (glufosinate), and
Gramoxone Extra (paraquat) were applied at 1.0, 1.0,
and 0.66 lb ai/a, respectively, 1 wk preflood and preplant.
In the multiple-bumdown treatment, herbicides were also
applied 3-wk preflood and preplant.
A shallow flood was established 2 d prior to
seeding with pregerminated 'Cypress' rice and drained 3
d later. The experiment was flush-irrigated as needed,
and the permanent flood was established 3-wk after
seeding. Nitrogen (150 lb/a) was applied in three equal
split applications at the 3-leaf, mid-tillering, and panicle
initiation growth stages.
The experiment was designed as a randomized
complete block with four replications in a factorial
arrangement. Factors were preplant vegetation
management and cover crops. Data were analyzed with
the SAS System (SAS Institute, 1988). Analysis of
variance with the GLM procedure was used to determine
significance. Means were compared using Fisher's
Protected LSD Test at the 5% level. Days to 50%
heading, plant height, and grain yield were determined.
Main effect means are shown in Tables 1 and 2
for 1995 and 1996, respectively. Significant interactions
occurred between cover crop and preplant vegetation
management for days to 50% heading, plant height, and
grain yield in each year of the study. These interactions
are depicted in Figures 1 to 6. LSD values are listed in
the figure captions, and the native cover crop is
considered the control.
There were no differences in days to 50%
heading due to preplant vegetation management with
cereal rye, ryegrass, and wheat cover crops in 1995
(Figure 1). Days to 50% heading were significantly
increased with all other cover crops when no herbicide
was used to control preplant vegetation. Within a cover
crop, there was generally little difference in maturity due
to the three bumdown herbicides with the exception of a
Roundup and berseem cover crop combination. Maturity
was delayed by 4 and 5 d when compared with Liberty
and Gramoxone Extra, respectively.
Days to 50% heading were not affected by
preplant vegetation management in the spring triticale,
multiple burdown, or Morey wheat treatments in 1996
(Figure 2). Maturity was increased in the berseem, white,
and red clover cover crops and in the ryegrass cover crop
when no burndown herbicide was used. In the berseem,
white, and red clover cover crops, maturity was
significantly delayed by Roundup and Gramoxone Extra
when compared with Liberty. Maturity was also delayed
by Roundup in the ryegrass cover crop and by
Gramoxone Extra in the wheat cover crop when
compared with Liberty.
Cereal rye and ryegrass were the only cover
crops for which preplant vegetation management
influenced plant height in 1995 (Figure 3). Plant height
was significantly reduced in these cover crops when
preplant vegetation was not controlled with a burndown
herbicide. Plant height within a cover crop was not
affected by burndown herbicide.
Preplant vegetation management within a cover
crop had no influence on plant height in 1996 (Figure 4).
Plant height was similar among the three burndown
herbicide and no-herbicide treatments.
The influence of cover crop and preplant
vegetation management on grain yield in 1995 is shown
in Figure 5. Grain yields were reduced when no
burndown herbicide was used on berseem, ladino, red,
and rose clovers and in ryegrass and native vegetation
cover crops. Rice yields from cereal rye and wheat were
not affected by preplant vegetation management. In the
yellow sweetclover cover crop, rice yield was reduced in
the no-herbicide treatment when compared with the
Gramoxone Extra treatment.
In 1996, grain yields were significantly reduced
in the berseem, white, and red clover cover crops and in
the ryegrass cover crop when no burdown herbicide was
used. In the multiple burndown treatment, yield was
significantly reduced with Gramoxone Extra. Roundup
and Liberty had no effect on grain production in this
treatment. Yields in the spring triticale, Morey wheat,
wheat, and native cover crops were not affected by
preplant vegetation management.
The influence of cover crop and preplant
vegetation management combination on days to 50%
heading, plant height, and maturity were quite variable
each year. The use of a planted cover crop does provide
more uniform and consistent preplant vegetation than can
normally be expected from native vegetation. The
negative influence imposed by some cover crops on rice
maturity, plant height, and grain yield does indicate that
cover crops in general are not necessarily suitable
alternatives to native vegetation. These influences were
significantly greater when no herbicide was used to
control preplant vegetation. Relying on natural
senescence of the cover crops or their control with
floodwater alone caused longer delays in maturity,
reduction in plant height, and significant yield reductions
Delayed maturity and reduced grain yields
experienced when rice is planted into some clovers and
the ryegrass cover crops can be attributed to poor stand
establishment and low stand densities. Density was not
determined in this study, however, it was observed that in
some treatments or treatment combinations, rice stands
were significantly reduced. In these situations, there was
a strong tendency for maturity to be delayed and yields to
be decreased. Adequate plant populations in
water-seeded rice are essential for optimum growth and
yield (LSU Agricultural Center, 1987).
It is not fully known what mechanisms are
involved for certain cover crops to negatively affect rice
plant growth and grain yield. The type of vegetation, the
amount of biomass produced, or allelopathic effects,
either individually or in combination, could explain the
interference observed. It was beyond the scope of this
study to identify these factors. It will be important to
further evaluate the influence of cover crops on rice plant
growth and grain yield. An understanding of the
interactions involved will afford the opportunity to better
manipulate cover crops to the benefit of no-till rice
The author would like to thank the Louisiana
Rice Research Board for supporting this research. The
author also extends appreciation to G.R. Romero, R.P.
Regan, D.M. Walker, and G.A. Meche for their technical
Bollich, P.K. 1996. Stand establishment in water-
seeded, minimum till rice as influenced by
water management and preplant vegetation
control. pp. 13-18. In Proc. South. Cons.
Till. Conf. for Sust. Ag. Special Pub. 96-
07. Univ. Of Tennessee, West Tennessee
Exp. Sta., Jackson, TN.
Eastman, J.S. 1986. Potential for the use of legume
cover crops, reduced tillage, and sprinkler
irrigation in Louisiana rice production.
Thesis. Louisiana State University. Baton
LSU Agricultural Center. 1987. Rice Production
Handbook. Louisiana Coop. Ext. Serv.
and Louisiana Agr. Exp. Stn. Pub. 2231,
Baton Rouge, LA.
SAS Institute. 1988. SAS/STAT User's Guide:
Version 6.03. Ed. SAS Inst., Cary, NC.
Table 1. Effect of preplant vegetation termination and cover crops on agronomic performance of
water-seeded, no-till Cypress rice. Rice Research Station, South Unit, Crowley, LA. 1995.
Main effect Days to 50% heading Plant height at 12% moisture
Preplant vegetation management (PVM) Mean
Roundup 88 36 6666
Gramoxone Extra 87 36 7029
Liberty 87 36 6918
None 94 35 4824
LSD (0.05): 1 1 437
Cover Crop (CC) Mean
Berseem clover 92 35 4960
Ladino clover 89 37 7180
Red clover 91 36 6354
Rose clover 89 37 7152
Yellow sweetclover 86 36 7120
Cereal rye 84 35 7128
Ryegrass 102 34 2453
Wheat 84 36 7402
Native 87 37 7483
LSD (0.05): 2 2 656
CV% 2.82 2.52 14.71
Table 2. Effect of preplant vegetation termination and cover crops on agronomic performance of
water-seeded, no-till Cypress rice. Rice Research Station, South Unit, Crowley, LA. 1996.
Main effect Days to 50% heading Plant height at 12% moisture
Preplant vegetation management (PVM) Mean
Roundup 91 33 7275
Gramoxone Extra 92 33 6914
Liberty 88 33 7863
None 95 34 6392
LSD (0.05): 1 1 275
Cover Crop (CC) Mean
Berseem clover 105 34 3410
White clover 92 34 7819
Red clover 96 34 6923
S. Triticale 87 32 7864
Multiple bumdown 87 32 8003
Morey wheat 87 32 7776
Ryegrass 96 34 6040
Wheat 88 33 7857
Native 87 31 8305
LSD (0.05): 2 2 413
CV% 2.49 3.42 8.28
DAYS TO 50% HEADING
ROUNDUP OGRAMOXONE LIBERTY NONE
Figure 1. Influence of cover crop and preplant vegetation management on days to 50% heading of Cypress
rice, 1995. LSD = 4 (P=0.05).
DAYS TO 50% HEADING
ROUNDUP OGRAMOXONE LIBERTY NONE
Figure 2. Influence of cover crop and preplant vegetation management on days to 50% heading of Cypress
rice, 1996. LSD = 4 (P=0.05).
PLANT HEIGHT (IN)
ROUNDUP OGRAMOXONE EJLIBERTY NONE
Figure 3. Influence of cover crop and preplant vegetation management on plant height of Cypress rice,
1995. LSD = 3 (P=0.05).
PLANT HEIGHT (IN)
ROUNDUP OGRAMOXONE LIBERTY NONE
Figure 4. Influence of cover crop and preplant vegetation management on plant height of Cypress rice,
1996. LSD = 4 (P=.05).
YIELD/A X1000 (LB/A)
ROUNDUP OGRAMOXONE ]LIBERTY NONE
Figure 5. Influence of cover crop and preplant vegetation management on grain yield of Cypress rice, 1995.
LSD = 1310 (P=0.05).
YIELD/A X1000 (LB/A)
ROUNDUP OGRAMOXONE J LIBERTY NONE
Figure 6. Influence of cover crop and preplant vegetation management on grain yeild of Cypress rice, 1996.
LSD = 824 (P=0.05).