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Group Title: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY-92-04
Title: Best lupine or vetch and N fertilizer management practice for optimizing corn ear leaf area, dry weight and N concentration
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Permanent Link: http://ufdc.ufl.edu/UF00056103/00001
 Material Information
Title: Best lupine or vetch and N fertilizer management practice for optimizing corn ear leaf area, dry weight and N concentration
Series Title: Agronomy research report
Physical Description: 17 leaves : ill. ; 28 cm.
Language: English
Creator: Hagendorf, Benjamin A
Gallaher, Raymond N
University of Florida -- Agronomy Dept
Publisher: Agronomy Department, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1992?]
 Subjects
Subject: Corn -- Fertilizers -- Florida   ( lcsh )
Cover crops -- Florida   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaves 9-10).
Statement of Responsibility: Benjamin A. Hagendorf and Raymond N. Gallaher.
General Note: Caption title.
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Bibliographic ID: UF00056103
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 62628485

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HISTORIC NOTE


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Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
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Copyright 2005, Board of Trustees, University
of Florida




l&1s-
Central Science
AG- library
Agronoy Research Report, AY-92-04 ,^ J 2 4 1932

Best Lupine or Vetch and N Fertilizer Y~-At mnif0orp acti =e for
Optimizing Corn Ear Leaf Area, Dry Weight-and-N-Coneentration


Benjamin A. Hagendorf and Raymond N. Gallaher
Participant in Student Science Training Program and Professor of
Agronomy, respectively, Agronomy Department, Inst. Food and Agr.
Sci., University of Florida, Gainesville, FL 32611

ABSTRACT

Sufficient leaf area, the area of leaves in relation to the
land area in which the plants are growing, dictates the level of
growth and nutrition of corn (Zea mays L.). The leaf area and
subsequently, the growth and yield, are influenced by nitrogen (N)
nutrition and crop management schemes. If cover crops (hairy vetch
{Vicia villosa L.}, lupine {Lupinus angustifolius L.}) are used and
specific management schemes are performed, then the ear leaf N
concentration, area, and weight will be positively affected. The
objective of this research was to determine the best lupine or
vetch management practice for maximizing corn ear leaf area,
weight, and N concentration. The management schemes included type
of tillage (no-tillage vs. conventional), use of cover crop, and
application of inorganic N. The cover crop was planted in the fall
and manipulated in the spring according to the various management
schemes before planting the corn. Ear leaves of corn were
collected from each separate plot and tested for ear leaf area, ear
leaf weight, and ear leaf N concentration. The N concentration was
determined using the Kjeldahl Method for N determination. The no-
tillage lupine mulch management scheme was found to be the most
economically efficient practice requiring only 50 kg N/ha of N
fertilizer to reach the sufficient N concentration level (2.70% N)
necessary for suitable corn. However, under vetch, the forage
treatments, both conventional and no-tillage, were found to be the
best practices since they were able to supply food as forage while
still requiring the least N fertilizer among the other vetch
treatments. Not enough N and improper management will result in
reduced plant yield and inefficiency with the use of resources.
This in turn leads to reduced production for export sales, reduced
ability to provide food to hungry people, and loss of profits by
corn producers. If corn could be produced sufficiently with
minimum tillage or N application, the crop could be produced at
less expense and with less labor and energy consumption.








INTRODUCTION
Pressures, responsibilities, and obligations are placed on
those in the food producing professions by the ever increasing
population. To face this problem, the farmland must be utilized
for growing crops on a year-round basis. The practices of minimum
tillage will aid in conserving the land and other resources while
practicing multiple cropping for food production.1

The term multiple cropping generally refers to growing more
than one annual food, feed, green manure, industrial, or ratoon
crop on land in one 12-month period. It is simply the growing of
more than one crop per year on the same soil. One major form of
multiple cropping is succession cropping, in which two or more
crops are grown in succession on the same land in one year. The
specific form of successive multiple cropping used in this case is
called double cropping. This is where two crops are grown in
sequence per year in contrast to other forms of multiple cropping,
where two crops are growing at the same time, for example.1

Mentioned earlier as a conserving method of land and
resources, minimum tillage is a term used to describe the smallest
possible disturbance of soil to produce a crop. This method
contrasts with the method now most widely used called conventional
tillage. This is the use of tillage implements such as plows to
turn over the land for depositing the seeds of a crop. A form of
minimum tillage called no-tillage is defined as "The opening of a
slot in the soil only sufficiently deep and wide to properly
deposit and cover seed".' Advantages of the no-tillage method
include reduction of erosion, the increase of field use,
conservation of water, reduction of labor, efficient use of time in
planting, and reduction of production costs.1

There are several different management schemes in use in
agriculture and each have their own benefits. The ones relevant to
this research include conventional tillage or no-tillage, already
discussed, and green manure, mulch, or foraging of the cover crop.


Green manure crops are grown for their soil improving
qualities or as a cover crop. The crop is plowed-in at the end of
the growing season or just prior to planting the succeeding crop.
In the case of legumes being used as a cover crop, using the crop
for a green manure requires tilling but supplies N to the soil for
the succeeding crop in a multicropping system.2

To use the cover crop as a mulch for the succeeding crop the
cover crop must be responsibly killed using contact herbicides such
as Roundup or Gramoxone.3 Mulches are valuable in multicropping
farming systems because of reduced erosion and pollution, moisture
conservation, lower soil temperatures in warm weather, higher
temperatures in cold weather, being a source of soil organic
matter and plant nutrients (i.e. legume mulch supplies N), reduced








weed growth, reduced Lesser Corn Stalk Borer infestation,
improvement in timeliness for planting of crops, fewer tillage
operations (i.e. no-tillage), and improved crop yield.3 It has
been shown that minimum tillage corn planted into hairy vetch and
crimson clover ({trifolium incarnatum L.} another widely used
legume) mixtures produced grain yields comparable to those obtained
by the application of 112 kg/ha of inorganic N in a University of
Delaware study.3

By using the cover crop as forage, feed for rumen animals, the
soil is protected from erosion since the roots left behind by the
animals keep the soil together. However, 90% of the plant is taken
for animal feed so therefore, the N supply available for the
succeeding crop is much less than a mulch or green manure. Even
though the use of a cover crop for forage allows the succeeding
crop to receive erosion prevention and some N, it becomes
profitable when the cover crop plant material is feeding livestock.

The use of a legume as the cover crop, or first crop, has
certain benefits to the soil and the crop which follows. The
legume generally has a symbiotic relationship with N fixing
bacteria. The bacteria live on the plant's roots, taking its needs
of photosynthate (i.e. glucose) from the plant while converting the
N in the atmosphere (N2) into NO3 or NO2, the sources of essential
N for plants.

Nitrogen is the largest required nutrient of corn (Zea mays
L.) and is required in the largest quantities compared to other
nutrients.4 As mentioned earlier, legumes are one source. They
are a source of organic N and can be used as a cover crop to be
sacrificed for a corn crop, for example, to be planted in
succession on the same land in the same year. A second source is
fertilizer which is inorganic and is applied in the form of
ammonia, NH4, or other forms such as NH4NO3 or NH4SO4.5

Sufficient leaf area, the area of leaves in relation to the
land area in which the plants are growing, dictates the level of
growth and nutrition of corn. The leaf area and subsequently, the
growth and yield, is influenced by N nutrition and crop management
schemes. Not enough N and improper management will result in
reduced plant yield, inefficiency in use of resource, reduced
production of food for man and animals, reduced production for
export sales to other countries, reduced ability to provide food to
hungry people, and loss of profits by corn producers. If an excess
of N is applied or the management scheme is excessive, then there
is a chance of polluting the ground water.5 However the corn crop
receives its N (organic or the applied inorganic), it is said to
have a sufficient level if the concentration in the ear leaf at
early silking and tasseling is between 2.70% and 4.0% N.6








The hypotheses listed below are in negative form. These null
hypotheses, as they are called, regard the treatment effects on the
corn.
I. Cover crops of lupine (Lupinus anqustifolius L.) or hairy
vetch (Vicia villosa L.) will not satisfy the N requirements of
corn.
II. Cover crops will not affect the ear leaf area, ear leaf
weight, nor ear leaf N concentration.
III. Inorganic N fertilizer will not be needed in any amount to
meet the N requirements of corn when corn follows the above cover
crops.
IV. Inorganic N fertilizer will not affect the ear leaf area,
ear leaf weight, nor ear leaf N concentration when corn follows the
above cover crops.
V. Management schemes used on the cover crops will not affect
the ear leaf area, ear leaf weight, nor ear leaf N concentration of
corn.

The objective of this research was to determine the best
lupine or vetch management practice for maximizing corn ear leaf
area, weight, and N concentration.

METHODS OR PROCEDURES
Two different species (vetch, lupine) of cover crops were
planted in October 1991 on four separate plots of land. Come
April, when the corn was planted, the winter cover crop was dealt
with and the land was manipulated in five different ways within
each plot of land.

The whole plot (main effects or management schemes)
manipulations were as follows: A) no-tillage and subsoil/mulch of
winter crop, B) no-tillage and subsoil/forage of winter crop, C)
conventional tillage and subsoil/green manure of winter crop, D)
conventional tillage and subsoil/forage of winter crop, E)
conventional tillage and subsoil/farrow (control). Furthermore,
each manipulation or main effect plot was separated into five sub
plots with increasing inorganic N applications from 0 kg N/ha to
268 kg N/ha in increments of 67 kg N/ha (1=0, 2=67, 3=134, 4=201,
5=268).

Table 1. is an example of 1 of 4 repetitions of each winter
crop group. The first number represents the repetition the second
number represents the whole plots 1) CT/forage, 2) CT/green
manure, 3) NT/mulch, 4) NT/forage, and 5) CT/fallow which were
randomized into four row plots so that none were favored. The
third number represents the N rate treatment (0, 67, 134, 201, 268)
which was randomized down the columns.

Four rows of five corn plants were planted on each plot and
treated accordingly. There was one border row of untreated plants
on each side (West side and East side) Each four row plot was 10
feet wide by 12 feet long, and between each plot was a two foot








border. The samples are collected by removing the ear leaf from
five random plants and placed in a paper bag on which was written
the cover crop, date, and plot number. These samples were then put
through a (Ll-3100) leaf area meter to obtain the sum of the ear
leaf area of the five leaves per treatment.

Corn ear leaves were dried in a forced air oven at 70 C for 24
hours and weighed on an analytical balance for dry matter weights.
These dry leaves were ground in a Wiley mill to pass a 2.00 mm
stainless steel screen and the mixed-ground samples were stored in
air tight and sterile plastic bags until they were analyzed.

To analyze for N the Kjeldahl Method for N Determination was
utilized.7 After weighing 100 mg of leaf tissue for N analysis,
3.2 g of catalyst (a 9:1 ratio of K2SO4:CuSO4), 10 ml of H2SO4, and
2 ml H202 were added in a test tube and digested for 6 hours on an
aluminum digestion block.8 Samples were brought to 75 ml volume,
stored in plastic bottles and analyzed on a Technicon II
Autoanalyzer to determine the concentration.

Ear leaf area, dry weight and N concentration values were
typed into a spreadsheet (Quattro Pro9) for manipulation and
transformation on a microcomputer. Statistical analysis was then
performed for a split-plot experimental design using MSTAT1.
Harvard Graphics" was used to plot relationships between N rates
and changes in leaf area, leaf dry weight or leaf N concentration.

RESULTS
All of the factors (ear leaf area, weight, and N
concentration), on the average, had a positive correlation to some
degree and all increased in value to the increasing N rates (Figure
1-6). The lines of the separate whole plots (management schemes),
however, start at different intercepts and fluctuate as they go
along the graph. For example the lupine CT-Forage whole plot had
a ear leaf area 28% higher then that of the fallow whole plot at no
N application, but only 9% higher at 268 kg N/ha application
(Figure 1). Also, at the 201 kg N/ha application there was less
than a 1% difference between the CT-Forage and the fallow whole
plots.

Table 2 shows the amount of N fertilizer necessary for each
management system to grow corn with sufficient N concentration
(2.70% to 4.0%)6 in the ear leaf. The NT-Mulch management system
from the corn crop grown after lupine required only about 50 kg
N/ha to reach sufficiency. In addition, the average leaf area of
the lupine NT-Mulch whole plot at sufficiency was about 2935 cm2
(sum of 5 leaves) and the dry weight was about 17.75 g. This
represented a 12% and 15% increase, respectively over the fallow
plots.

From the lupine cover crop treatment, the corn ear leaf area
(Table 3 and Figure 1) was positively correlated since it increased








as the rates of N fertilizer application increased with all whole
plots up to 201 kg N/ha. The best whole plot at no applied N
fertilizer (0 kg N/ha) was CT-Forage with an ear leaf area of 2996
cm2 while the worst was the fallow (control) whole plot with an ear
leaf area of 2145 cm2. This CT-Forage whole plot with no applied
N was 28% better than the fallow whole plot. The best whole plot
at maximum amount of applied N fertilizer (268 kg N/ha) was also
CT-Forage with an ear leaf area of 3365 cm2 while the worst was the
fallow whole plot with an ear leaf area of 3067 cm2. Hence, CT-
Forage was 9% better at that N level. All ear leaf areas were
averaged according to whole plots and N levels. The averages
represent the ear leaf areas of 20 subplots (Table 3). Therefore,
on the average, the ear leaf area was 18% better at the highest
level of applied N (268 kg N/ha) than at the 0 kg N/ha applied N
level for all whole plots.

The corn ear leaf dry weight from the lupine cover crop
treatment (Table 4 and Figure 2) was positively correlated since it
increased as the rates of N fertilizer application increased with
all whole plots up to 201 kg N/ha. The best whole plot at no
applied N fertilizer (0 kg N/ha) was CT-Forage with a dry weight of
18.90 g while the worst was the fallow (control) whole plot with a
dry weight of 11.16 g. This CT-Forage whole plot with no applied
N was 41% better than the fallow whole plot. The best whole plot
at maximum amount of applied N fertilizer (268 kg N/ha) was also
CT-Forage with a dry weight of 22.45 g while the worst was the
fallow whole plot with a dry weight of 19.00 g. Hence, CT-Forage
was 15% better at that N level. Lastly, on the average, the ear
leaf dry weight was 26% better at the highest level of applied N
(268 kg N/ha) than at the 0 kg N/ha applied N level for all whole
plots.

The corn ear leaf N concentration from the lupine cover crop
treatment (Table 5 and Figure 3) was positively correlated since it
increased as the rates of N fertilizer application increased with
all whole plots up to 268 kg N/ha. The best whole plot at no
applied N fertilizer (0 kg N/ha) was CT-Forage with an ear leaf N
concentration of 2.40% while the worst was the fallow (control)
whole plot with an ear leaf N concentration of 1.65%. This CT-
Forage whole plot with no applied N was 31% better than the fallow
whole plot. The best whole plot at maximum amount of applied N
fertilizer (268 kg N/ha) was also NT-Forage with an ear leaf N
concentration of 3.21% while the worst was the CT-Forage whole plot
with an ear leaf N concentration of 3.06%. Hence, NT-Forage was 5%
better at that N level. Lastly, on the average, the ear leaf N
concentration was 33% better at the highest level of applied N (268
kg N/ha) than at the 0 kg N/ha applied N level for all whole plots.

From the vetch cover crop treatment, the corn ear leaf area
(Table 6 and Figure 4) was hardly correlated since it did not
significantly increase as the rates of N fertilizer application
increased. Individually however, the conventional tillage whole








plots (CT-Forage and CT-Green Manure) did increase to the third and
second levels of N application, respectively. Fallow increased
significantly also but only to the first applied N level. On the
other hand, the no tillage whole plots had no significant increase
to a 0.05 level of probability as seen on Table 8 by the mean
separation of the values.

The corn ear leaf dry weight from the vetch cover crop
treatment (Table 7 and Figure 5) was positively correlated since it
increased as the rates of N fertilizer increased with all the whole
plots to at least the third N level (134 kg N/ha). The best whole
plot at no applied N fertilizer (0 kg N/ha) was NT-Mulch with an
ear leaf dry weight of 16.78 g while the worst was the fallow
(control) whole plot with an ear leaf dry weight of 10.01 g. This
NT-Mulch whole plot with no applied N was 40% better than the
fallow whole plot. The best whole plot at maximum amount of
applied N fertilizer (268 kg N/ha) was the fallow whole plot with
an ear leaf dry weight of 20.47 g while the worst was the CT-Forage
whole plot with the an ear leaf dry weight of 19.11 g. Hence, the
fallow whole plot was 7% better at that N level. Lastly, on the
average, the ear leaf N concentration was 26% better at the highest
level of applied N (268 kg N/ha) than at the 0 kg N/ha applied N
level for all whole plots.

The corn ear leaf N concentration from the vetch cover crop
treatment (Table 8 and Figure 6) was positively correlated since it
increased as the rates of N fertilizer application increased with
all whole plots up to 268 kg N/ha. The best whole plot at no
applied N fertilizer (0 kg N/ha) was NT-Mulch with an ear leaf N
concentration of 2.01% while the worst was the fallow whole plot
with an ear leaf N concentration of 1.33%. This NT-Mulch whole
plot with no applied N was 34% better than the fallow whole plot.
The best whole plot at maximum amount of applied N fertilizer (268
kg N/ha) was also NT-Mulch with an ear leaf N concentration of
3.15% while the worst was the CT-Green Manure plot with the an ear
leaf N concentration of 2.93%. Hence, NT-Mulch was 7% better at
that N level. Lastly, on the average, the ear leaf N concentration
was 41% better at the highest level of applied N (268 kg N/ha) than
at the 0 kg N/ha applied N level for all whole plots.

DISCUSSION
To find the best winter-cover crop and management scheme to be
used to efficiently grow a sufficient corn crop, the effects of two
legume cover crop treatments and five separate management schemes
were examined. It was found that for an increasing amount of N
fertilizer applied the factors (ear leaf area, dry weight, and N
concentration) also increased respectively. Each treatment reached
the accepted ear leaf N sufficiency level of 2.70%-4.00%6 at some
point along the increasing N fertilizer applications. However,
this point was reached as a result of how successful the particular
cover crop and the management scheme used together were in
providing the corn crop with a sufficient amount of N and a








situation favorable for adequate nutrient uptake. Nevertheless,
all the management schemes need some amount of N fertilizer to
reach the 2.70% N6 sufficiency level. For the farmer, this amount
is economically significant.

Among the lupine cover crop treatments, the NT-Mulch
management scheme needed the least amount of N fertilizer to reach
within the sufficiency range. Since this treatment only needed 50
kg N/ha, it can be inferred that the rest of the N was supplied by
the lupine cover crop and the fact that the crop was planted under
and grown over a mulch of the lupine. With a mulch, all of the
plant material is present to allow for an ample supply of N to be
slowly mineralized into the soil corn root zone. However, a green
manure also supplies adequate N to the soil yet it is
conventionally tilled into the soil. This requires more labor and
fuel than no-tillage and is detrimental as far as erosion and water
conservation are concerned.

The treatment that required the most N fertilizer was the
fallow, or control treatment. It required 140 kg N/ha which is 64%
more than what the NT-Mulch required to reach the same 2.70% N
sufficiency level. Regardless, the ear leaf area and dry weights
for each whole plot at sufficiency are not that significantly
different. Meaning that the plants from the schemes requiring more
N fertilizer to become sufficient, and therefore healthy, are not
any larger or heavier than the plants requiring much less N
fertilizer. Thus, the same corn crop produced (under these
conditions) from fallow land could possibly be produced at a lower
cost by utilizing a well planned and well executed management
scheme such as a no-tillage lupine mulch.

Under vetch, the forage treatments were the most efficient in
supplying the corn crops N due to both only requiring 150 kg N/ha
under that management practice. This is especially good because
the crop received a sufficient amount of N while the vetch cover
crop was also taken away as a forage. This forage could be used to
feed the farmer's animals, if any, or could be sold to make a
profit. Therefore, here two purposes were served by providing the
N to the soil for the succeeding corn crop and by providing a
forage. In this case, however, there is another plus. The no-
tillage forage performed just as well as the conventional tillage.
Hence, money, labor, and fuel can be saved by performing a no-
tillage forage system as opposed to a performing conventional-
tillage system.

To determine the best management practice, cost and what is
needed from the crop must be taken into consideration. The more N
fertilizer required for the corn crop to reach within the
sufficiency range of 2.70%-4.00% N6 the higher the cost is for the
farmer producing the crop. Let us say it cost the farmer $0.66 per
kg of N fertilizer. This would mean that the farmer would have to
spend $59.40 per hectare (not including price of lupine cover crop









or fuel and labor to plant this extra corp) more to produce the
same crop from fallow land instead of using a lupine no-tillage
mulch management practice, If the farmer wants to utilize his
lupine cover crop as a forage, he would save money by not needing
to buy forage and by paying $6.60 less per hectare to produce to
corn crop by lupine no-tillage forage than by just the fallow
treatment. The same principle can be applied to the vetch cover
crop management practices.

The first hypothesis could not be rejected due to the fact
that all management practices needed some amount o N fertilizer to
reach the prescribed sufficiency range of 2.70%-4.00% N needed for
a suitable corn crop. Hypothesis number two was not correct
because with both cover crops there was significant difference
between the fallow (control) and the rest of the treatments as far
as ear leaf area, dry weight, and N concentration are concerned.
The third hypothesis was also not rejected because all management
practices need some amount of N fertilizer to reach the sufficiency
range for a suitable and healthy corn crop. Hypothesis number four
was not correct because it was shown by the data that for all
treatments that as the applied N fertilizer rate increased so did
the ear leaf areas, dry weights, and N concentrations, to some
significant degree. Lastly, hypothesis number five was proved
partially correct since through both cover crops there was no
definite difference. For example, in the lupine the best
management practice was NT-Mulch, however, with vetch it was the
worst.

REFERENCES

1. Gallaher, Raymond N., 1980. Multiple Cropping Minimum
Tillage. University of Florida MMT-1.

2. Gallaher, Raymond N., and Val J. Eylands. 1985. Green manure
cropping systems and benefits. Agronomy Research Report
AY-85-11.

3. Gallaher, Raymond N., 1980. Value of residues, mulches or
sods in cropping systems. University of Florida MMT-5.

4. Olson, R.A., and D.H. Sander. 1988. Corn production. in, Corn
and Corn Improvement. pp. 639-686. Ed. G.F. Sprague, and
J.W. Dudley. Number 18 the Agronomy series. American
Society of Agronomy, Inc., Crop Science Society of America,
Inc., and Soil Science Society of America, Madison,
Wisconsin, USA.

5. Personal communication with Dr Raymond N. Gallaher

6. Jones, J. Benton, Jr., Benjamin Wolf, and Harry A. Mills.
1991. Plant Analysis Handbook. Micro-Macro Publishing, Inc.
Athens, Ga.








7. Jones, J. Benton, Jr., 1991. Kjeldahl Method for Nitrogen
Determination. Micro-Macro Publishing, Inc. Athens, Georgia.

8. Gallaher, Raymond N., C.O. Weldon, and J.G. Futral. 1975. An
aluminum block digester for plant and soil analysis. Soil
Sci. Soc. Amer. Proc., 39:803-806.

9. Quattro Pro, ver.1.0. 1989. A spreadsheet software program.
Borland International, Inc. Scotts Valley, CA

10. MSTAT, ver.4.0. 1985. Microcomputer statistical program.
Michigan State University.

11. Harvard Graphics, ver.2.0. 1987. Software Publishing
Corporation. Mountain View, CA.



ACKNOWLEDGEMENTS
The authors appreciate Mr. James R. Chichester for laboratory
and computer assistance and Mr. Howard C. Palmer for leaf sampling
assistance. Funding for this research came from a grant from the
Tennessee Valley Authority, a grant from Pioneer Hi-Bred,
International, Inc. and the Agronomy Department, Institute of Food
and Agricultural Sciences, University of Florida.










Table 1. Example of the randomization of a field plot of corn
following either lupine or vetch.
----------------NORTH DIRECTION----------------
134* 132 135 131 133

152 151 153 155 154

141 145 142 143 144

113 114 111 112 115

125 121 124 122 123

* 1S no.=replication no.l; 2id no.=management scheme; and
3rd no.=nitrogen rates.


Table 2. Amount of applied nitrogen fertilizer required to reach
a minimum sufficiency concentration of 2.70% N in corn ear leaves
and their estimated ear leaf area (LA) and dry weight (DW) at
that range.


COVER CROP


LUPINE


MANAGEMENT


CT-Forage
CT-Green manure
NT-Mulch
NT-Forage
Fallow (control


Applied N
Fertilizer
--Kg/ha--
58
75
50
130
) 140


Estimated Estimated
Leaf Area Dry Weight
--cm sq.-- ---g---
3059 18.74
3082 18.77
2935 16.95
3048 19.74
2944 18.35


CT-Forage
CT-Green manure
NT-Mulch
NT-Forage
Fallow (control)


VETCH


150
180
205
150
195


3362
3045
3027
2862
3097


20.11
17.87
17.77
17.94
21.09









Table 3. Corn ear leaf area affected by lupine-tillage management
and N fertilizer. (Average of five ear leaves)
Nitrogen level (kg/ha)
Management 0 67 134 201 268 Average
----- Square centimeter/5 leaves ------
CT-forage 2996 3066 3096 3242 3365 3153 v

CT-Green manure 2708 3082 3080 3404 3254 3106 v

NT-Mulch 2835 2969 3283 3157 3206 3090 v

NT-Forage 2438 2835 3061 3413 3156 2981 vw

Fallow 2145 2724 2917 3222 3067 2815 w

LSD=152
Average 2624 d 2935 c 3087 bc 3288 a 3210 ab
CV=7.96%


CT-Forage = Lupine harvested for forage followed by conventional
tillage soil preparation. CT-Green Manure = Lupine turned under
with conventional tillage. NT-Forage = Lupine harvested for forage
followed by direct seeding with in-row subsoil no-tillage planter.
NT-Mulch = Direct seeding in lupine with in-row subsoil no-tillage
planter. Fallow = No winter cover crop, area kept clean tilled as
a control treatment. Values in rows within each management
treatment not followed by the same letter (a,b,c,d,e) are
significantly different at the 0.05 level of probability according
to LSD. Values in columns within a N level not followed by the
same letter (v,w,x,y,z) are significantly different at the 0.05
level of probability according to Duncan's multiple range test.


Corn ear leaf area affected by tillage-
lupine management and N fertilizer


60 100 150 200
Kg/ha Nitrogen


260 300


- CT Forage -- CT Green Manure NT Mulch
- NT Forage -- Fallow


Figure 1


- -------









Table 4. Corn ear leaf weight affected by lupine-tillage
management and N fertilizer. (Average of five ear leaves)
Nitrogen level (kg/ha)
Management 0 67 134 201 268 Average
------------ Grams/5 leaves -----------
CT-forage 18.90 18.71 19.62 21.25 22.45 20.19 v

CT-Green manure 15.86 18.82 18.41 22.37 20.65 19.22 v

NT-Mulch 16.53 18.17 20.02 20.33 20.65 19.14 v

NT-Forage 13.47 17.16 19.91 21.68 19.97 18.44 vw

Fallow 11.16 16.41 18.13 20.61 19.00 17.06 w

LSD=1.24
Average 15.18 d 17.85 c 19.22 b 21.25 a 20.54 a
CV=7.96%
CT-Forage = Lupine harvested for forage followed by conventional
tillage soil preparation. CT-Green Manure = Lupine turned under
with conventional tillage. NT-Forage = Lupine harvested for forage
followed by direct seeding with in-row subsoil no-tillage planter.
NT-Mulch = Direct seeding in lupine with in-row subsoil no-tillage
planter. Fallow = No winter cover crop, area kept clean tilled as
a control treatment. Values in rows within each management
treatment not followed by the same letter (a,b,c,d,e) are
significantly different at the 0.05 level of probability according
to LSD. Values in columns within a N level not followed by the
same letter (v,w,x,y,z) are significantly different at the 0.05
level of probability according to Duncan's multiple range test.


Corn ear leaf weight from tillage-
lupine management and N fertilizer

9A.


0 50 100 150 200
Nitrogen Applied in kg/ha


250 300


- CT Forage CT Green Manure NT Muloh
-*- NT Forage -- Fallow


Flpure 2












Table 5. Corn ear leaf N affected by lupine-tillage management
and N fertilizer. (Average of five ear leaves)
Nitrogen level (kq/ha)
Management 0 67 134 201 268 Average
-------------- Percent ---------------
CT-forage 2.40 vc 2.72 vb 2.80 vab 3.04 va 3.06 va 2.80

CT-Green manure 2.21 vc 2.64 vb 2.83 vab 3.11 va 3.10 va 2.78

NT-Mulch 2.24 vc 2.79 vab 2.76 vb 3.03 vab 3.07 va 2.78

NT-Forage 1.85 we 2.44 vb 2.69 vb 3.12 va 3.21 va 2.66

Fallow 1.65 wd 1.97 we 2.64 vb 2.96 va 3.10 va 2.46

LSD=.30
Average 2.07 2.51 2.74 3.05 3.11
CV=7.96%
CT-Forage = Lupine harvested for forage followed by conventional
tillage soil preparation. CT-Green Manure = Lupine turned under
with conventional tillage. NT-Forage = Lupine harvested for forage
followed by direct seeding with in-row subsoil no-tillage planter.
NT-Mulch = Direct seeding in lupine with in-row subsoil no-tillage
planter. Fallow = No winter cover crop, area kept clean tilled as
a control treatment. Values in rows within each management
treatment not followed by the same letter (a,b,c,d,e) are
significantly different at the 0.05 level of probability according
to LSD. Values in columns within a N level not followed by the
same letter (v,w,x,y,z) are significantly different at the 0.05
level of probability according to Duncan's multiple range test.


Corn ear leaf N affected by tillage
lupine management and N fertilizer


0 60 100 150 200 250 300
Kg/ha Nitrogen
- CT Forage CT Green Manure NT Muloh
-- NT Forage Fllow


Figure 3









Table 6. Corn ear leaf area affected by vetch-tillage management
and N fertilizer. (Average of five ear leaves)
Nitrogen level (kg/ha)
Management 0 67 134 201 268 Average
----- Square centimeter/5 leaves ------
CT-forage 2763 vc 3032 vbc 3404 va 3228 vab 3345 vab 3154

CT-Green manure 2751 vb 3150 va 3229 vwa 2961 vab 3195 va 3057

NT-Mulch 3064 va 3153 va 3171 vwa 3012 va 3268 va 3134

NT-Forage 3039 vab 2874 vb 2928 vb 3295 va 3146 vab 3056

Fallow 1987 wb 3069 va 3100 vwa 3294 va 3389 va 2968

LSD=340
Average 2721 3069 3166 3158 3269
CV=7.96%
CT-Forage = Vetch harvested for forage followed by conventional
tillage soil preparation. CT-Green Manure = Vetch turned under
with conventional tillage. NT-Forage = Vetch harvested for forage
followed by direct seeding with in-row subsoil no-tillage planter.
NT-Mulch = Direct seeding in vetch with in-row subsoil no-tillage
planter. Fallow = No winter cover crop, area kept clean tilled as
a control treatment. Values in rows within each management
treatment not followed by the same letter (a,b,c,d,e) are
significantly different at the 0.05 level of probability according
to LSD. Values in columns within a N level not followed by the
same letter (v,w,x,y,z) are significantly different at the 0.05
level of probability according to Duncan's multiple range test.


Corn ear leaf area affected by tillage-
vetch management and N fertilizer


0 50 100 160 200
Kg/ha Nitrogen


250 300


CT Forage CT Green Manure NT Muloh
- NT Forage Fallow


Figure 4









Table 7. Corn ear leaf weight affected by vetch-tillage management
and N fertilizer. (Average of five ear leaves)
Nitrogen level (kq/ha)
Management 0 67 .134 201 268 Average
------------ Grams/5 leaves -----------
CT-forage 14.80vb 16.17vb 20.46va 19.01vwa 19.11va 18.02

CT-Green manure 15.25vb 18.23va 18.87va 17.41wab 18.91va 17.73

NT-Mulch 16.78vb 17.57vab 18.83vab 17.63wab 19.95va 18.15

NT-Forage 15.62vc 16.34vbc 17.52vabc 19.28vwa 19.12vab 17.58

Fallow 10.01wc 18.68vab 18.40vb 21.36va 20.47vab 17.85

LSD=2.81
Average 14.51 17.51 18.82 18.94 19.57
CV=7.96%
CT-Forage = Vetch harvested for forage followed by conventional
tillage soil preparation. CT-Green Manure = Vetch turned under
with conventional tillage. NT-Forage = Vetch harvested for forage
followed by direct seeding with in-row subsoil no-tillage planter.
NT-Mulch = Direct seeding in vetch with in-row subsoil no-tillage
planter. Fallow = No winter cover crop, area kept clean tilled as
a control treatment. Values in rows within each management
treatment not followed by the same letter (a,b,c,d,e) are
significantly different at the 0.05 level of probability according
to LSD. Values in columns within a N level not followed by the
same letter (v,w,x,y,z) are significantly different at the 0.05
level of probability according to Duncan's multiple range test.





Corn ear leaf weight from tillage-
vetch management and N fertilizer

24
2241 ----- --------------------------------------..-.....-...............
d 20 ---------

Y 18

1.0... .----- ---- ......... ---- .....
m ig


10 j
S14 -- -


0 so 100 150 200 250 300
Nitrogen Applied in kg/ha
CT Forage -- CT GrOen Manure NT Muloh
-- NT Forage -- Fallow

Figure 6




UNIVERSITY OF FLORIDA

tl 1 i IIt I Ill l I i [ 1i t lt
3 1262 05586 4267

Table 8. Corn ear leaf N affected by vetch-tillage management
and N fertilizer. (Average of five ear leaves)
Nitrogen level (kg/ha)
Management 0 67 134 201 268 Average
-------------- Percent ---------------
CT-forage 1.70 2.45 2.56 2.89 3.00 2.52 v

CT-Green manure 1.96 2.11 2.43 2.70 2.93 2.43 v

NT-Mulch 2.01 2.51 2.57 2.59 3.15 2.57 v

NT-Forage 1.92 2.06 2.59 2.84 3.02 2.49 v

Fallow 1.33 1.83 2.31 2.66 2.97 2.22 w

LSD=0.16
Average 1.78 e 2.19 d 2.49 c 2.74 b 3.01 a
CV=7.96%
CT-Forage = Vetch harvested for forage followed by conventional
tillage soil preparation. CT-Green Manure = Vetch turned under
with conventional tillage. NT-Forage = Vetch harvested for forage
followed by direct seeding with in-row subsoil no-tillage planter.
NT-Mulch = Direct seeding in vetch with in-row subsoil no-tillage
planter. Fallow = No winter cover crop, area kept clean tilled as
a control treatment. Values in rows within each management
treatment not followed by the same letter (a,b,c,d,e) are
significantly different at the 0.05 level of probability according
to LSD. Values in columns within a N level not followed by the
same letter (v,w,x,y,z) are significantly different at the 0.05
level of probability according to Duncan's multiple range test.




Corn ear leaf N affected by tillage
vetch management and N fertilizer


3.1 ------------------------------- ^--
e
r 2.6
0
n 2.1 -- --.--- ------- --
N 1. ...---- -------------
1.1
0 60 100 150 200 250 300
Kg/ha Nitrogen
CT Forae -- CT Green Manure -- NT Muloh
-- NT Forage Fallow

Figure 6




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