Environmental index

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Environmental index
Hildebrand, Peter E.
North Florida Farming Systems Research and Extension Project].,
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Project Proposal Submitted by

North Florida Farming Systems Research and Extension


October 29, 1982


One of the salient characteristics of FSR/E is that of performing

on-farm experimentation that allows the farmer to directly contribute

to the evaluation and development of new technology. This process

considers the social, economic and physical constraints that farmers

face, and allows for the development of technology within these


It is known that some technologies are satisfactory for some

farmers, yet others find it undesirable, i.e. they are constrained

or:unable to adopt it for some reason. Determination of the constraints

which hinder a technology from successful adoption is central to the

FSR/E process. Once the factors that limit the adoption of a certain

technology are identified, researchers are in a better position to

alter the technology and correct any deficiencies.

In recent years,attempts at defining the constraints facing farmers

have become complicated and cumbersome and have shown only modest

results. Examples might include whole farm linear programming models

or models involving farmer decision making trees. In each case, the

attempt has been made to delineate constraining factors of production

(e.g. land, labor capital, physical environment,tastes and preferences,

etc.) for a farmer or group of farmers and thus define an environment

that may or may not be suitable for certain technologies. In effect,

such methods must detect and define all possible constraints that affect

the adoption of new technology before an attempt is made to place

specific technology in a specific recommendation domain. Determining

constraints is difficult in this manner even by highly skilled

social scientists who have an intimate knowledge of the culture

and environment in which they are operating.

An exciting method of defining farmer constraints, delineating

recommendation domains and evaluating the economic aspects of new

technology has recently come to light(Appendix I1). Based on a method

of evaluating varietal stability by plant breeders, Environmental

Indexing allows researchers to evaluate technology over a large range

of environments (as influenced by physical, social and economic factors)

without the necessity of defining constraints before-hand.

The method basically consists of comparing new and old technologies

under a wide range of on-farm environments. The performance of these

tehcnologies are then studied relative to the environments they were

subjected to. Because most technologies are developed or evolve under

specific environments (i.e. on experiment station research plots or

subsistence farmers' fields) one would expect their performance to vary

under different environments. With environmental indexing it is

possible to group farmers according to the performance of technologies

on their farms. Those farms that show similar responses to various

technologies can then be classified into specific recommendation domains-

and can be assumed to possess similar production constraints be they

physical or socioeconomic. From this potnt, determination of specific

constraints is simply a matter of observing appropriate characteristics

that are common to farmers in the same domain.

Problem Statement:

Environmental indexing has been used to analyse on-farm data

drawn from recent Farming Systems research in Malawi. The results

are encouraging and indicate that environmental indexing may be a

powerful method of analysing new technologies. However, further

experimentation and experience are needed for adequate verification

of the method.


Environmental indexing canbe successfully utilized to evaluate

on-farm trials and help to determine and define recommendation domains

and farmer constraints.


The objective of this research project is to obtain enough on-farm

research data to adequately test the environmental indexing methodology.

Thi, will be accomplished by augmenting existing on-farm research projects

of the North Florida FSR/E program.


The North Florida FSR/E has determined that wheat may be an

important new crop to farmers in North Florida. However, many questions

pertaining to wheat production practices remain unanswered to researchers

and farmers alike. It is in these areas that additional on-farm research

is being conducted by the North Florida FSR/E team and will be augmented

to test the environmental indexing methodology. Inithis way resources

used to evaluate thepotential of environmental indexing will also

supplement the on-farm research efforts of the North Florida project.

The following three research projects will be enhanced with

additional on-farm trials that,could include farms in Madison,

Hamilton, Suwannee, Columbia, and Lafayette counties.

1. Response of Wheat to Tillage Method (Appendix 2)

Originally planned to include five farms, this project

will be expanded to fifteen on-farm trials with one supporting

on-station ;trial.

2. Florida 301 Wheat Response to K Fertilization (Appendix 3)

This experiment as originally planned contains 11 treatments

and will be replicated 4 times on 3 farms. With the addition

of the Environmental Indexing study, the number of farms will

be increased by 10 with one replication per farm. Collaborating

with J. Kidder, Soil Science.

3. Wheat Response to Six Fertilization Programs and Effects on

Residual Potassium Availability to soybeans. (Appendix 4).

Earlier FSR/E research plans included three on-farm tests

with six treatments replicated four times. Expansion under

the new plan would include 10 more on-farm trials, each

replicated once per farm. Collaborating with C. Hiebech,



Bruce Dehm, a M.S. candidate in FRE has agreed to move to Live Oak

to take on major responsibility in carrying out the additional on-farm

trials. He is presently on a 1/3 assistantship under the Cooperative

Agreement with USDA/OICD. During the time Mr. Dehm is working full-

time on this project, he will receive a full-time assistantship from

these same funds.


Additional funding from a Strengthening Grant will be needed

and is requested as follows:


Fertilizer and misc. supplies $ 4,000

Transportation 3,000

TOTAL O.E. $ 7,000

OPS 3,000,

Total funding requested $10,000


Increasing interest in the Farming Systems Research and Extension

(FSR/E) approach to technology generation, evaluation and promotion is

focusing interest in on-farm research. Described is a form of research

design and analysis that explicitly incorporates variation in farmer .

management as well as in soils and climate, to help agronomists evaluate

responses to treatments and partition farmers into recommendation domains.

Only simple pre-programmed calculators are necessary. Mean treatment

yields at each location are used as an "environmental index". Treatment

results are regressed on environmental index to determine the differential

effects of each to environment.' A frequently distribution of confidence

intervals within partitioned groups helps in final decisions for selection

of superior treatments.

Data from an unreplicated trial on 14 farms in 2 villages in.Malawi

are analyzed. Design is a 2 X 2 factorial with 2 maize (Zea mays L.)

cultivars and 2 fertilizer treatments (0 and 30 kg N/ha). Results show

that in the poorer maize environments, the local flint cultivars are superior

to an improved semi-flint composite, with or without fertilizer. The

composite yields more than the local material with or without fertilizer

in the better environments. In all cases there is a marked and significant

response to fertilizer.




A study (Wright, 1982) recently completed shows that moldboard

plowing significantly increased grain yield over yields obtained

from disked plots. These trials were performed where a till pan

of high resistance (over 400 psi) exists within 8" inches of the

soil surface (Wright, 1982). It is not known that the same yield

response will occur where soil resistance is less. Further, it is

unclear that moldboard plowing will be effective from an economic

viewpoint, given the low average yields that have been achieved in

the study areas.


The objective of the trial is to determine the yield response

of wheat, particularly, Florida 301, to tillage methods. The economic

benefits or loss that results from each practice will be determined.


The trials will be conducted on-farm, with a supporting on-station

trial. Each participating farmer will be asked to prepare four strips

by moldboard plowing and four strips by disking A completely randomized

design with four replications will be used.




Potassium fertilization recommendations for wheat in Florida

have been determined, based largely on work at the Quincy ARC. Soils

in the FSR/E study area are generally poorer than those farther west,

and the 60 bu/ac wheat yields achieved at Quincy may not be achievable

in the FSR/E study area. During the 1981-82 growing season, for example,

wheat yields on the 14 farms (Suwannee and Columbia Counties) monitored

by the FSR/E team averaged only 12 bu/ac.

The 1981-82 growing season was particularly poor. Nonetheless,

farmers, extensionists, and FSR/E personnel all feel that average yields

of about 30 bu/ac may be the norm in the study area.

Potassium fertilization at the levels currently recommended may
therefore be inappropriate in the study area. Enterprise records on the

14 farms show that fertilizer was a major variable cost in producing

wheat for these farmers, often the most costly single input. Economically,

lower potassium fertilizer use may be optimal. Further, plant response

to high potassium fertilizer level may be limited by other' factors such

as soil moisture and disease. The deep sands common in the study area do.

not retain moisture well. None of the farmers who kept records during

the 1981-82 growing season sprayed for disease control, and probably less

than half of all wheat growers in the study area did so.


The objective of the trial is to determine wheat response, particularly

Florida 301, to five potassium fertilizer levels. Three common soil types

in the study area, which vary in clay content in the upper 6-10" inches

of the profile, will be included.


The trials will be performed on-farm with a split plot design

with four replications Five potassium fertilizer

levels will be employed: (1) 0 lbs/ac K20, (2) 40 Ibs/ac K20, (3)

80 Ibs/ac K20, (4) 120 Ibs/ac K20, and (5) 160 Ibs/ac K20. At each

potassium level, two nitrogen and phosphorus fertilization practices will

be followed. They are: (1) 70 Ibs/ac N in two applications, one pre-

plant and one post emergence and 60 Ibs/at P205 in one pre-plant appli-

cation and (2) the particular farmer's practice. The latter nitrogen

treatment will vary from farm to farm.

Data taken will include grain yield and initial and final soil test

potassium levels. Enterprise records will be maintained. Plant response

will be correlated with applied potassium and initial soil test potassium


Collaborator: J. Kidder, Soil Science

10 sands only

15 w/clay

3 full 4 reps

7-12 2 rep only





Many wheat growers, especially those who double crop, do not

follow standard university recommendations when fertilizing wheat. Of

9 farmers who received soil test results prior to planting wheat in

the fall of 1981 for example, only one grower applied suggested rates

of N, P, and K. Similarly, many growers prefer to make only one, late

fertilizer application. They follow this practice because they fear

losses due to leaching of N and K applied prior to planting and because

they feel that late K application increases the residual K available

for the following crop.


The objective of this trial is to compare wheat grain yields,

particularly Florida 301 yields, under several fertilization programs

and to determine the effects of those programs on residual potassium



The trials will be conducted on-farm with a supporting trial at

the Live Oak ARC. A randomized complete block design will be used, with

four replications. The following treatments will be used:

(1) application of 35,lbs/a N, 60 Ibs/a P205 and 120 Ibs/a K20

followed by a post-emergence application of 35 Ibs/a N.

(2) a single, late (early Feb.) application of 70 Ibs/a N, 60 Ibs/a

K205 and 120 Ibs/a K20

(3) a pre-plant application of 26 Ibs/A N, 45 Ibs/A P205,
and 90 Ibs/A K20 and a post-emergence application of 26 Ibs/A N.

(4) a single, late application of 52 Ibs/A N, 45 Ibs/A P205,
and 90 Ibs/A K20.

(5) a pre-plant application of 15 lbs/A N, 30 Ibs/A P205, and
60 Ibs/A K20 followed by a post-emergence application of 20 Ibs/A N.

(6) a single, late, application of 35 Ibs/A N, 30 Ibs/A P205,
and 60 Ibs/A K20.

Data collected will include wheat grain yield. Soil potassium
levels will be determined at harvest. Providing that there are
significant differences between residual potassium levels between
treatments, the same area will then be used as a trial involving
soybean response to residual and applied potassium.