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Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; 882
Title: Estimation of dry matter production and nutrient removal by corn silage in Florida
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 Material Information
Title: Estimation of dry matter production and nutrient removal by corn silage in Florida
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 33 p. : ill. ; 28 cm.
Language: English
Creator: Overman, Allen R., 1937-
Rhoads, Fred ( Frederick Milton )
Publisher: Agricultural Experiment Station, University of Florida
Place of Publication: Gainesville
Publication Date: 1991
 Subjects
Subject: Corn -- Silage -- Florida   ( lcsh )
Plants -- Effect of nitrogen on -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 4-5).
Statement of Responsibility: Allen R. Overman and Fred Rhoads.
General Note: Cover title.
General Note: "October 1991."
Funding: Bulletin (University of Florida. Agricultural Experiment Station) ;
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Volume ID: VID00001
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Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page
    Table of Contents
        Table of Contents
    List of Tables
        Page i
    List of Figures
        Page ii
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
    Tables
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Figures
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
    Back Cover
        Back Cover
Full Text


1;9:46 a--yJ
October 1991
C;


Bulletin 882


0"
d'' n.j


Estimation of Dry Matter Production

and Nutrient Removal by Corn Silage in Florida




Allen Overman and Fred Rhoads



























Agricultural Experiment Station
Institute of Food and Agricultural Sciences
University of Florida
J.M. Davidson, Dean



















Estimation of Dry Matter Production

and Nutrient Removal by Corn Silage in Florida




Allen Overman and Fred Rhoads



























Authors
Allen R. Overman is professor, Department of Agricultural Engineering, and Fred M. Rhoads is professor, Department of Soil
Science, University of Florida, Gainesville FL 32611.









Contents


List of tables ..................................................... ...............................

List of figures ...................................................... ............................ ii

Preface ........................................................... ................................. 1

Introduction ....................................................... ............................. 1

Data analysis ..................................................... ............................. 1

D ry m matter .................................................................................... 1

Plant N concentration ............................... .............. ...............2

Plant P concentration ................................................................3

Plant K concentration................................................................3

Plant nutrient removal ................................................. ..............3

Summary and conclusions.............................................. .............. 4
References ...................................................................................... 4









List of tables
Page
6 1. Dependence of accumulated dry matter on
plant population, applied N, and time after
planting for corn at Quincy, Florida (1978).
6 2. Dependence of accumulated dry matter on
plant population and applied N at 91 days
after planting for corn at Quincy, Florida
(1978).
6 3. Comparison of measured and estimated dry
matter at 91 days after planting corn at
Quincy, Florida (1978).
7 4. Dependence of maximum dry matter on
plant population and time after planting for
corn at Quincy, Florida.
7 5. Dependence of plant N concentration on
plant population, applied N, and time after
planting for corn at Quincy, Florida (1978).
8 6. Dependence of plant N concentration on
plant population and applied N at 91 days
after planting for corn at Quincy, Florida
(1978).
8 7. Comparison of measured and estimated
plant N concentration at 91 days for corn at
Quincy, Florida (1978).
8 8. Dependence of maximum plant N concen-
tration on time after planting for Corn at
Quincy, Florida.
9 9. Dependence of plant P concentration on
plant population, applied P, and time for corn
at Quincy, Florida (1978).


Page
9 10. Dependence of plant P concentration on
plant population and applied P at 91 days
after planting for corn at Quincy, Florida
(1978).
9 11. Dependence of plant P concentration on
time after planting for corn at Quincy,
Florida.
10 12. Dependence of plant K concentration on
plant population, applied K, and time after
planting for corn at Quincy, Florida (1978).
10 13. Dependence of plant K concentration on
plant population and applied K at 91 days
after planting for corn at Quincy, Florida
(1978).
10 14. Dependence of plant K concentration on
time after planting for corn at Quincy,
Florida;
11 15. Estimated plant response with time after
planting for 90,000 plants/ha for corn at
Quincy, Florida.
11 16. Estimated plant response to applied N for
90,000 plants/ha at 100 days after planting for
Corn at Quincy, Florida.
11 17. Estimated recovery of applied P for 90,000
plants/ha at 100 days after planting for corn
at Quincy, Florida.
11 18. Estimated recovery of applied K for 90,000
plants/ha at 100 days after planting for corn
at Quincy, Florida.









List of figures
Page
12 1. Dependence of dry matter on applied N and
plant population at 91 days after planting for
corn at Quincy, Florida (1978).
13 2. Correlation of dry matter (Y) with the
logistic model for corn at Quincy, Florida
(1978). Lines drawn from Equations (3) and
(4).
14 3. Response of dry matter to applied N and
plant population at 91 days after planting for
corn at Quincy, Florida (1978). Curves drawn
from Equations (3) and (4).
15 4. Correlation of maximum dry matter (Ym)
with time (t) for corn at Quincy, Florida
(1978). Line drawn from Equation (6).
16 5. Dependence of maximum dry matter (Ym)
on time (t) and plant population for corn at
Quincy, Florida (1978). Curve drawn from
Equation (6).
17 6. Dependence of dry matter on applied N,
plant population, and time after planting for
corn at Quincy, Florida (1978). Curves drawn
from Equations (3), (4), and (6).
18 7. Dependence of plant N concentration on
applied N and plant population at 91 days
after planting for corn at Quincy, Florida
(1978).
19 8. Correlation of plant N concentration (Ne)
with applied N for corn at Quincy, Florida
(1978). Line drawn from Equation (7).
20 9. Response of plant N concentration (Ne) to
applied N and plant population at 91 Days
after planting for corn at Quincy, Florida
(1978). Curve drawn from Equation (8).
21 10. Correlation of maximum plant N concen-
tration (Ne) with time after planting (t) for
corn at Quincy, Florida (1978). Line drawn
from Equation (9).
22 11. Dependence of maximum plant N concen-
tration (N ) on time after planting (t) for corn
at Quincy, Florida (1978). Curve drawn from
Equation (10).


Page
23 12. Response of plant N concentration to
applied N, plant population, and time after
planting for corn at Quincy, Florida (1978).
Curves drawn from Equation (10).
24 13. Dependence of plant P concentration on
applied P, plant population, and time after
planting for corn at Quincy, Florida (1978).
25 14. Dependence of plant P concentration on
applied P and plant population at 91 Days
after planting for corn at Quincy, Florida
(1978).
26 15. Correlation of plant P concentration (PC)
with time after planting (t) for corn at Quincy,
Florida (1978). Line drawn from Equation
(11).
27 16. Dependence of plant P concentration (P,)
on time after planting (t) for corn at Quincy,
Florida (1978). Curve drawn from Equation
(11).
28 17. Dependence of plant K concentration on
applied K, plant population, and time after
planting for corn at Quincy, Florida (1978).
29 18. Dependence of plant K concentration on
applied K and plant population at 91 Days
after planting for corn at Quincy, Florida
(1978)
30 19. Correlation of plant K concentration (K)
with time after planting (t) for corn at Quincy,
Florida (1978). Line drawn from Equation
(12).
31 20. Dependence of plant K concentration (K,)
on time after planting (t) for corn at Quincy,
Florida (1978). Curve drawn from Equation
(12).
32 21. Estimated dry matter, plant N concentra-
tion and plant N removal with time after
planting for corn at Quincy, Florida. Curves
drawn from Equations (4), (6), and (11).
33 22. Estimated Response of dry matter, plant
N concentration, and plant N removal to
applied N at 100 Days after planting for corn
at Quincy, Florida. Curves drawn from
Equations (4), (6), and (11).









Preface
The purpose of this bulletin is to provide docu-
mentation of procedures for estimation of dry
matter production and N removal by corn under
Florida conditions. Such documentation is needed
by professionals (engineers, advisors, managers,
and regulators) in an age of increased accountabil-
ity and liability. The research community can
serve a vital role in this responsibility. In essence,
this report was developed to ultimately serve
practitioners in the field. Additional articles, based
on this material are planned for technical journals
and in an extension format.
The equations used in this analysis may be
viewed as regression models. While the models are
not the ultimate in sophistication (biological and
mathematical), they do provide a useful tool to aid
in management decisions. Furthermore, they are
easy to implement on a pocket calculator.

Introduction
Corn (Zea mays L.) is grown extensively in the
United States for both grain and silage. It offers a
suitable crop in Florida for animal feed production
and as a receptacle for nutrients (N, P, and K) in
-land application systems for waste management
(agricultural and urban).
The purpose of this bulletin is to describe quanti-
tative procedures for estimation of dry matter
production and nutrient removal for corn silage
under Florida conditions as related to applied N,
plant population, and stage of growth. These three
input factors operate in combination to affect
output.
The most recent treatise on corn production is
that by Sprague and Dudley (1988), which dis-
cussed a wide range of factors relevant to the
subject. Numerous studies have focused on plant
population (Aldrich et al., 1975; Colville and
McGill, 1962; Duncan, 1972; Karlen and Camp,
1985; Maftoun, 1965; Rhoads and Russell, 1977;
Rhoads and Stanley, 1979; Rhoads et al., 1988; and
Stanley and Rhoads, 1975). Other works have
emphasized response to applied N (Overman, 1981;
Rhoads and Stanley, 1979; Rhoads et al., 1988; and
Robertson et al., 1968).
The present analysis is based upon field work at
the University of Florida Agricultural Research and
Education Center at Quincy, Florida. Some results
have been reported earlier (Rhoads and Stanley,
1979 and Rhoads et al., 1988). The study was
conducted during 1977-78, but only 1978 data are


used due to carry-over of N into 1977 from the
previous bahiagrass. Pioneer 3368A hybrid was
planted on March 30, 1978 on Dothan loamy fine
sand (fine loamy, siliceous, thermic Plinthic
Kandiudults). Fertilizer was applied in four equal
amounts at 2, 6, 8, and 10 weeks after planting.
Treatments included five applied N rates (0, 0.5, 1,
2, 3, and 5 g/plant) for plant populations of 60,000
and 90,000 plants/ha (24,000 and 36,000 plants/
acre). The N-P-K ratio was held constant at 1-0.3-
0.8 for all treatments. Irrigation was applied by
overhead sprinklers when soil-water tension at 15-
cm depth reached 20 centibars. Other experimen-
tal details can be found in Rhoads et al. (1988).
Results here are reported as g/plant (applied N,
dry matter, and N removal) to facilitate calcula-
tions. These procedures should not be extrapolated
beyond a plant population of 90,000 plants/ha.

Data analysis

Dry Matter
Data are listed in Table 1 for dry matter as
related to plant population, applied N, and growth
stage. Casual inspection of the data shows that dry
matter increases with time after planting, in-
creases with applied N, and decreases with popula-
tion. We now proceed to develop mathematical
relationships to describe these variations.
Attention is first focused on response to applied
N at 91 days after planting. Dry matter averages
and standard deviations are listed in Table 2 and
graphed in Figure 1. Appreciable variation among
replications is apparent. Following earlier reports
by Overman and Blue (1990) on bahiagrass
[Paspalum notatum Flugge] and Overman et al.
(1990) on bermudagrass [Cynodon dactylon (L.)
Pers.], the logistic equation is used to relate dry
matter to applied N, viz.
(1)
y mY
Ym


1 + exp


N- N1/
N'


where


Y =
Y
N =
N, =
N' =


dry matter, g/plant
maximum dry matter at high N, g/plant
applied N, g/plant
applied N to reach Ym/2, g/plant
characteristic N of the soil-plant system,
g/plant








Equation (1) contains the three parameters Ym, N1,
and N', which are evaluated from the data. Now
Equation (1) may be linearized to the form


In -1 -N112
L Y I = V


The procedure is to choose Ym to provide the best
straight line on a semilog plot. Results are given in
Table 3 and Figure 2 for Y = 270 g/plant, where
the lines are drawn from
(3)

60,000 plant/ha: Y = 270
1 + exp ( N.+.1.221


(4)

90,000 plants/ha: Y= 270
1 + exp N-1.74


The correlation coefficients for the lines in Figure 2
are -0.9970 and -0.9989 for 60,000 plants/ha and
90,000 plants/ha, respectively. Results are also
plotted in Figure 3, where the curves are drawn
from Equations (3) and (4). Close agreement
between equations and data may be noted, which
justifies Equation (1) for this analysis.
The next step is to account for change in dry
matter with time. Estimates of maximum dry
matter (Ym), made from examination of Table 1, are
listed in Table 4. Following work by Allhands and
Overman (1989) on corn, the probability function is
used to relate dry matter to time, viz.


Y.
Y -
mm1~2


S+ erf --
( v2a


where


Ymm

t
t

0a


= maximum dry matter at high
applied N, g/plant
= maximum dry matter at high
applied N and at peak time, g/plant
= time after planting, days
= time to mean of yield distribution,
days
= standard deviation of yield distribu-
tion, days


and erf is the error function. Equation (5) contains
the three parameters (Ymm, t, and a ) which are
evaluated from data. The procedure is to choose
Ymm to produce the best straight line on a probabil-
ity graph between Ym/Ym and t. Results are given
in Table 4 and Figure 4 for Ymm = 320 g/plant.
Figure 4 is used to estimated and a, vi.


S= t(Y /320 = 50%) = 70 days
= t (Y/320 = 84%) t (Ym/320 = 16%)=20 days
2
With these values of parameters, Equation (5)
becomes
(6)
320 t 70
Y 2 [ 1 + erf ( ) ]
2 28



The line in Figure 4 is drawn from Equation (6).
Results are also shown in Figure 5, where the curve
is drawn from Equation (6). Close agreement
between the equation and data may be noted.
Equations (3), (4), and (6) may now be
combined to estimate dependence of dry matter on
applied N and elapsed time for the two plant
populations. These results are shown in Figure 6.
Reasonable agreement between equations and data
may be noted. Best agreement is at 91 days, as
expected from the procedure used. This is also the
sampling date of most interest for estimating silage
production.

Plant N concentration
Dependence of plant N concentration on plant
population, applied N, and growth stage is given in
Table 5. Inspection of the data reveals an increase
in N concentration with applied N and a decrease
with elapsed time. Quantitative relationships are
now developed.
Again attention is focused on 91 days after
planting. Averages and standard deviations are
listed in Table 6 and shown in Figure 7. Appre-
ciable variation among replications is apparent.
Due to scatter in the data, plant N concentration is
averaged between the two plant populations (Table
7). Values appear to approach 1.25% at high
applied N. Figure 8 shows a semilog plot of (1.25 -
N.) versus applied N, where the line is drawn from








(11)


In (


1.25


N+ 1.18
1.28


with a correlation coefficient of-0.9982. Close
agreement between Equation (7) and the data is
apparent. Results are also shown in Figure 9,
where the curve is drawn from
(8)

Nc = 1.25 [1- exp(- N- 8)


Estimates of maximum plant N concentration,
Ncm, at high N for other elapsed times are made
from Table 5 and are listed in Table 8. It is esti-
mated that Ncm is approaching 0.80 at larger times.
Values of (N.m 0.80) versus time are plotted in
Figure 10, where the line is drawn from
(9)

N = 0.80 + 2.20 exp ( 35)


Close agreement between Equation (9) and the data
may be noted.
Dependence of plant N concentration on applied
N and elapsed time can be estimated from
(10)

N, = 1.25 [.80 + 2.20 exp (- )]I exp(- N+ 1.18)


Results are shown in Figure 12, where the curves
are drawn from Equation (10).

Plant P concentration
Dependence of plant P concentration on plant
population, applied P, and growth stage is given in
Table 9 and is plotted in Figure 13. Variation
among replications is indicated in Table 10 and
Figure 14 for 91 days after planting. Based on
Figures 13 and 14, there is no clear trend between
plant P and applied P. Values are averaged across
applied P, as listed in Table 10. Correlation be-
tween P -0.22 and t is shown in Table 11 and
Figure 15, where the line is drawn from


PC = 0.22 + 0.28 exp t1035)



Time dependence of plant P concentration is shown
in Figure 16, where the curve is drawn from Equa-
tion (11).

Plant K concentration
Dependence of plant K concentration on plant
population, applied K, and growth stage is given in
Table 12 and Figure 17. Experimental variation
among the four reps is shown in Table 13 and
Figure 18 for 91 days after planting. As with
applied P, no clear trends are evident from Figures
17 and 18. Average values across applied K are
listed in Table 14 and plotted in Figure 19, where
the line is drawn from
(12)

Kc = 5.40 exp (- t 35)


Time dependence of plant K concentration is shown
in Figure 20, where the curve is drawn from Equa-
tion (12).

Plant nutrient removal
Results from dry matter and nutrient analyses
are now used to estimate plant nutrient accumula-
tion and removal. A plant population of 90,000
plants/ha is selected for this purpose.
Dry matter is estimated from


(13)


1 + erf t( 7)
Y = 160 -1 28 )0-
1 + exp (- 74)
2.69 /


Plant N concentration is calculated from Equation
(10). Plant N accumulation, NT, is calculated from


(14)


N = 10 Y Nc









Time dependence of dry matter, plant N concentra-
tion, and plant N accumulation is given in Table 15
for applied N of 2.5 and 5.0 g/plant. Results are
also shown in Figure 21. Plant response at 100
days after planting (silage stage) to applied N is
shown in Table 16 and Figure 22. It is apparent
that dry matter, plant N concentration, and plant
N accumulation all increase with applied N. Nitro-
gen recovery (N/N) decreases with applied N,
reaching a value of 52% for applied N of 5 g/plant
(450 kg/ha).
Plant accumulation, P,, of applied P at 100 days
after planting is listed in Table 17, where plant P
concentration is calculated from Equation (11). For
applied N and P of 5 g/plant and 1.5 g/plant,
respectively, P recovery is 34%.
Table 18 gives values of accumulated K, Kr, at
100 days after planting, where plant K concentra-
tion is calculated from Equation (12). Potassium
recovery is 87% for applied N and K of 5 g/plant
and 4.2 g/plant, respectively.

Summary and conclusions
Results have been discussed for estimation of dry
matter, and plant N removal for corn silage under
irrigation in Florida. Input factors include applied
N, plant population, and growth stage (time after
planting).
Procedures are best illustrated through an
example.
Assume: t = 100 days after planting
plant population = 75,000 plants/ha
(30,000 plants/acre)
N = 2.5 g/plant
S 188 kg/ha
S (168 lb/acre)


Estimate: Y


N
NT


Recovery


S 170 g/plant
S 12.8 t/ha
(5.7 tons/acre)
S 1.08%
S 138 kg/ha
S (123 lb/acre)


Equation (13)


Equation (10)
Equation (14)


N/N
138/188
73%


This compares with 44% recovery efficiency for
applied N of 5 g/plant (450 kg/ha, 400 lb/acre).


References
1. Aldrich, S.R., W.O. Scott, and E.R. Long. 1975.
Modern corn production. 2nd ed. A & L Publi-
cations, Champaign, IL.
2. Allhands, M.N. and A.R. Overman. 1989.
Effects of municipal effluent irrigation on
agricultural production and environmental
quality. Agric. Engr. Dept., Univ. of Fla.
Gainesville, FL pp. 377.
3. Colville, W.L. and D.P. McGill. 1962. Effect of
rate and methods of planting in several plant
characteristics and yield of irrigated corn.
Agron. J. 54: 235-239.
4. Duncan, W.G. 1972." Plant spacing, density,
orientation, and light relationships as related
to different corn genotypes." Proc. 27th Annual
Corn and Sorghum Res. Conf. Am. Seed Trade
Assoc., Washington D.C.
5. Karlen, D.L. and C.R. Camp. 1985. Row
spacing, plant population, and water manage-
ment effects on corn in the Atlantic Coastal
Plain. Agron. J. 77: 393-398.
6. Maftoun, M. 1965. Effects of plant population
and rate and placement of fertilizer on yield
and nutrient uptake of corn on Leon fine sand.
Ph.D. dissertation, University of Florida,
Gainesville, FL.
7. Overman, A.R. 1981. Irrigation of corn with
municipal effluent. Trans. Amer. Soc. Agr.
Engr. 24: 74-76, 80.
8. Overman, A.R. and W.G. Blue. 1990. Dry
matter production and nitrogen removal by
Pensacola bahiagrass in Florida. Fla. Agric.
Exp. Sta. Bull. 880. Gainesville, FL. 80 pp.
(In press.)
9. Overman, A.R., F.M. Rhoads, R.L. Stanley, Jr.,
and O.C. Ruelke. 1990. Estimation of dry
matter production and nitrogen uptake by
Coastal bermudagrass in Florida. Fla. Agric.
Exp. Sta. Bull. 883. Gainesville, FL. 74 pp.
10. Rhoads, F.M. and J.C. Russell. 1977. Corn
production with irrigation in north Florida.
Agric. Res. and Educ. Center, Quincy Res. Rep.
77-2.
11. Rhoads, F.M. and R.L. Stanley, Jr. 1979.
Effect of population and fertility on nutrient
uptake and yield components of irrigated corn.
Soil and Crop Sci. Soc. Fla. Proc. 38: 78-81-.









12. Rhoads, F.M., F.G. Martin, and R.L. Stanley,
Jr. 1988. Plant population as a guide to N
fertilization of irrigated corn. J. Fert. Issues 5:
67-71.
13. Robertson, W.K., L.G. Thompson, Jr., and L.C.
Hammond. 1968. Yield and nutrient removal by
corn (Zea mays L.) for grain as influenced by
fertilizer, plant population, and hybrid. Proc.
Soil Sci. Soc. Amer. 32: 245-249.


14. Sprague, G.F. and J.W. Dudley (Ed). 1988.
Corn and corn improvement. American Society
of Agronomy, Madison, Wisconsin.
15. Stanley, R.L., Jr. and F.M. Rhoads. 1975.
Response of corn (Zea mays, L) to population
and spacing with plow-layer soil water manage-
ment. Soil and Crop Sci. Soc. Fla. Proc.
34:127-130.










Table 1. Dependence of accumulated dry matter on plant population, applied, N, and time after planting for corn at Quincy, Florida
(1978).

Population Applied N Dry Matter, g/plant
plants/ha g/plant

Date 3/30 5/11 5/23 6/8 6/21
t, days 0 42 54 70 911

60,000 0 7 51 82 170
1 12 44 85 185
2 13 45 110 211
3 17 53 116 224
5 16 64 133 248

90,000 0 8 50 46 95
1 12 38 66 114
2 14 46 89 142
3 15 54 103 164
5 16 44 121 209

't = days after planting.


Table 2. Dependence of accumulated dry matter on plant population and applied N at 91 days after planting for corn at Quincy,
Florida (1978).

Population Applied N Dry Matter1 Relative Error
plants/ha g/plant g/plant %

60,000 0 170- 49 29
1 185 ? 46 25
2 211 16 8
3 224 7 30 13
5 248 T 37 15

90,000 0 95 T 28 29
1 114T 17 15
2 142 T34 24
3 164 T 31 19
5 209 T 40 19
1Avg. T Std. Dev. (4 reps.).


Table 3. Comparison of measured and estimated dry matter at 91 days after planting corn at Quincy, Florida (1978).1
A
Population Applied N Y (270/Y)-1 Y
plants/ha g/plant g/plant g/plant

60,000 0 170 0.588 166
1 185 0.460 189
2 211 0.280 209
3 224 0.205 226
5 248 0.0887 247


90,000 0 95 1.84 93
1 114 1.37 116
2 142 0.901 142
3 164 0.646 166
5 209 0.292 208

'Y= dry matter.
A
Y from Equations (3) and (4).










Table 4. Dependence of maximum dry matter on plant population, and time after planting for corn at Quincy, Florida.'
A
Population t Ym Ym/320 Ym
plants/ha days g/plant g/plant

60,000 42 17 0.053 26
54 67 0.209 67
70 142 0.444 157
91 270 0.844 270


90,000 42 22 0.069 26
54 78 0.244 67
70 156 0.488 157
91 270 0.844 270


Avg. 42 20 0.061 26
54 72 0.225 67
70 149 0.466 157
91 270 0.844 270
't = days after planting.
Y = maximum dry matter at high N.
Am
Y, = from Equation (6).


Table 5. Dependence of plant N concentration on plant population, applied N, and time after planting for corn at Quincy, Florida
(1978).

Population Applied N N Concentration, %
plants/ha g/plant


Date 3/30 5/11 5/23 6/8 6/29
t, days 0 42 54 70 91
60,000 0 2.20 1.28 1.22 0.82
1 2.20 1.46 1.37 1.10
2 2.39 1.78 1.41 1.14
3 2.32 1.86 1.33 1.23
5 2.76 2.24 1.43 1.19

90,0000 1.86 1.25 0.90 0.71
1 2.07 1.45 1.15 0.90
2 2.34 1.82 1.53 1.17
3 2.51 2.01 1.73 1.17
5 2.65 2.35 1.62 1.29

't = days after planting.










Table 6. Dependence of plant N concentration on plant population and applied N at 91 days after planting for corn at Quincy, Florida
(1978).

Population Applied N N Concentration' Relative Error
plants/ha g/plant % %

60,000 0 0.82 7 0.32 39
1 1.10 0.09 8
2 1.14 0.16 14
3 1.23 7 0.12 10
5 1.19 T 0.12 10

90,000 0 0.71 0.17 24
1 0.90 7 0.05 6
2 1.17 0.16 14
3 1.17 0.05 4
5 1.29 0.10 8

'Avg. T Std. Dev. (4 reps.).



Table 7. Comparison of measured and estimated plant N concentration at 91 days for corn at Quincy, Florida (1978).'
A
Population Applied N N, 1.25-Nc No
plant/ha g/plant % % %

60,000 0 0.82 0.43
1 1.10 0.15 -
2 1.14 0.11
3 1.23 0.02
5 1.19 0.06

90,000 0 0.71 0.54
1 0.90 0.35 -
2 1.17 0.08
3 1.17 0.08
5 1.29 -

Avg. 0 0.76 0.49 0.75
1 1.00 0.25 1.02
2 1.16 0.09 1.15
3 1.20 0.05 1.20
5 1.24 0.01 1.24

'N = plant N concentration.
Ac
N, = from Equation (8).

Table 8. Dependence of maximum plant N concentration on time after planting for corn at Quincy, Florida.1
A
t Ncm Nm-0.80 N
days % % %
42 2.60 1.80 2.60
54 2.10 1.30 2.08
70 1.60 0.80 1.61
91 1.25 0.45 1.25

't =days after planting.
N =maximum plant N concentration at high applied N.
N,=estimated from Equation (9).









Table 9. Dependence of plant P concentration on plant population, applied P, and time for corn at Quincy, Florida (1978).

Population Applied P P Concentration, %
plants/ha g/plant
Date 3/30 5/11 5/23 6/8 6/29
t, days 0 42 54 70 91'
60,000 0 0.42 0.33 0.25 0.20
0.3 0.35 0.30 0.27 0.24
0.6 0.38 0.26 0.24 0.20
0.9 0.39 0.27 0.22 0.23
1.5 0.38 0.24 0.23 0.24

90,000 0 0.38 0.28 0.26 0.26
0.3 0.36 0.20 0.21 0.25
0.6 0.35 0.21 0.24 0.22
0.9 0.36 0.22 0.22 0.22
1.5 0.34 0.24 0.21 0.21

60,000 Avg. 0.38 0.28 0.24 0.22
Std. Dev. 0.025 0.035 0.019 0.020

90,000 Avg. 0.36 0.23 0.23 0.23
Std. Dev. 0.015 0.032 0.022 0.022


't = days after planting.


Table 10. Dependence of plant P concentration on plant population and applied P at 91 days after planting for corn at Quincy,
Florida (1978).

Population Applied P P Concentration' Relative Error
plants/ha g/plant % %
60,000 0 0.20 + 0.04 20
0.3 0.24 0.05 20
0.6 0.20 7 0.04 20
0.9 0.23 T 0.03 15
1.5 0.24 7 0.04 15

90,000 0 0.26 T 0.05 20
0.3 0.25 ? 0.05 20
0.6 0.22 7 0.02 10
0.9 0.22 T 0.03 10
1.5 0.21 ? 0.02 10
'Avg. 7 Std. Dev. (4 reps).

Table 11. Dependence of plant P concentration on time after planting for corn at Quincy, Florida.'
A
t Pc PC-0.22 Pc
days % % %
42 0.37 0.15 0.36
54 0.26 0.04 0.26
70 0.23 0.01 0.23
91 0.22 0.22

't = days after planting.

P = plant P concentration (avg.).
A
Pc = estimated from Equation (11).










Table 12. Dependence of plant K concentration on plant population, applied K, and time after planting for corn at Quincy, Florida
(1978).


Population Applied K
plants/ha g/plant


K Concentration, %


Date 3/30 5/11 5/23 6/8 6/29
t,days 0 42 54 70 91'


60,000





90,000





60,000


90,000


Avg.
Std. Dev.

Avg.
Std. Dev.


't = days after planting.

Table 13. Dependence of plant K concentration on plant population and applied K at 91 days after planting for corn at Quincy,
Florida (1978).

Population Applied K K Concentration' Relative Error
plants/ha g/plant % %

60,000 0 1.75 T 0.48 27
0.8 1.48 7 0.44 30
1.7 1.49 7 0.21 14
2.5 1.58 7 0.06 4
4.2 1.78 T 0.19 11

90,000 0 1.88 7 0.54 29
0.8 1.65 7 0.17 10
1.7 2.02 T 0.38 19
2.5 1.91 7 0.27 14
4.2 2.04 T 0.35 17

'Avg. 7 Std. Dev. (4 reps).

Table 14. Dependence of plant K concentration on time after planting for corn at Quincy, Florida.1
A
t Kc K
days % %
42 4.25 4.73
54 4.20 3.77
70 2.98 2.79
91 1.76 1.88

't = days after planting.

Kc= plant K concentration.
A
K,= estimated from Equation (12).










Table 15. Estimated plant response with time after planting for 90,000 plants/ha for corn at Quincy, Florida.'

t Y N, NT Y N, NT
days g/plant % g/plant g/plant % g/plant
N = 5.0 g/plant N = 2.5 g/plant

40 16 2.69 0.43 12 2.56 0.31
50 39 2.22 0.87 28 2.11 0.59
60 76 1.86 1.41 56 1.77 0.99
70 124 1.60 1.98 91 1.52 1.38
80 172 1.40 2.41 126 1.33 1.68
85 192 1.32 2.53 141 1.25 1.76
90 209 1.25 2.61 154 1.19 1.83
95 222 1.19 2.64 163 1.13 1.84
100 231 1.13 2.62 170 1.08 1.84
105 238 1.09 2.59 175 1.04 1.82
110 242 1.05 2.54 178 1.00 1.78
115 245 1.02 2.50 180 0.966 1.74
120 247 0.986 2.44 181 0.938 1.70

't = time after planting.
Y = dry matter.
N,= plant N concentration.
NT= plant N removal.

Table 16. Estimated plant response to applied N for 90,000 plants/ha at 100 days after planting for corn at Quincy, Florida.1

Applied N Y Nc NT N/N
g/plant g/plant % g/plant

0 103 0.689 0.71 -
1 129 0.935 1.21 1.21
2 157 1.05 1.65 0.82
3 185 1.10 2.04 0.68
5 231 1.13 2.61 0.52
'Y=dry matter yield.
N = plant N concentration.
NT = plant N removal.
N1N = recovery of applied N.

Table 17. Estimated recovery of applied P for 90,000 plants/ha at 100 days after planting for corn at Quincy, Florida.'

Applied N Applied P Y P, PT P/P
g/plant g/plant g/plant % g/plant

0 0 103 0.22 0.23 -
1 0.3 129 0.22 0.28 0.93
2 0.6 157 0.22 0.35 0.58
3 0.9 185 0.22 0.41 0.46
5 1.5 231 0.22 0.51 0.34
1Y = dry matter yield.
P = plant P concentration.
PT= plant P removal.
P/P=recovery of applied P.

Table 18. Estimated recovery of applied K for 90,000 plants/ha at 100 days after planting for corn at Quincy, Florida.'

Applied N Applied K Y K. KT K,/K
g/plant g/plant % g/plant g/plant

0 0 103 1.58 1.63 -
1 0.8 129 1.58 2.04 2.55
2 1.7 157 1.58 2.48 1.46
3 2.5 185 1.58 2.92 1.17
5 4.2 231 1.58 3.65 0.87
'Y = dry matter yield.
Kc = plant K concentration.
KT= plant K removal.
K/K = recovery of applied K.












400


4-) -
S100 -
0

0a

0 0 I 4I I
4-)

l 60, 000 plants/ha


L 300




200











0 1 2 3 4 5 6


Applied N, g/plant

Figure 1. Dependence of dry matter on applied N and plant population at 91 days after planting for corn at
Quincy, Florida (1978).








10 I I

t = 91 days Symbol plants/ha

o 60,000

x 90,000


I







N
.1








.01 I i I --
0 1 2 3 4 5 6

Applied N, g/plant

Figure 2. Correlation of dry matter (Y) with the logistic model for corn at Quincy, Florida (1978). Lines drawn from
Equations (3) and (4).









400






300


200


1 2 3 4 5 6


Applied N,


g/plant


Figure 3. Response of dry matter to applied N and plant population at 91 days after planting for corn at Quincy,
Florida (1978). Curves drawn from Equations (3) and (4).

























60

50

40

E 30
>1


20 40 60 80 100


t. days


Figure 4. Correlation of maximum dry matter (Y,) with time (t) for corn at Quincy, Florida (1978). Line drawn from
Equation (6).










400 1


Symbol plants/ho

o 60. 000
3x 90, 000
300





C
a
r" 200 -


0 l0



100






0
0 20 40 60 80 100 120

t, days


Figure 5. Dependence of maximum dry matter (Ym) on time (t) and plant population for corn at Quincy, Florida
(1978). Curve drawn from Equation (6).











400 1 1 1 1

90,000 plants/ha


300

t, days


200 91



070




4-l




a


0 0










x-3x-x- 54
Appl d Nplnts/h/plant
300
ca

91

200


70

100

54

42

0 1 2 3 4 5 6


Applied N, 9/plant

Figure 6. Dependence of dry matter on applied N, plant population, and time after planting for corn at Quincy,
Florida (1978). Curves drawn from Equations (3), (4), and (6).












1.5










90,000 plants/ha



.5

St = 91 days




-i
0
L














0 1 2 3 4 5 6
0
C
0


C --


















0
.5-








0 1 2 3 4 5 6


Applied N, 9/plant

Figure 7. Dependence of plant N concentration on applied N and plant population at 91 days after planting for
corn at Quincy, Florida (1978).





























in
I

(J










.01
0 1 2 3 4 5


Applied N, g/plant

Figure 8. Correlation of plant N concentration (Ne) with applied N for corn at Quincy, Florida (1978). Line drawn
from Equation (7).








































1 2 3 4 5


Applied N.


g/plant


Figure 9. Response of plant N concentration (N,) to applied N and plant population at 91 Days after planting for
corn at Quincy, Florida (1978). Curve drawn from Equation (8).


2. 0






1.5






1.0


.5






0. O
0


























d
I
E
z








.1 I I 1 I
0 20 40 60 80 100 120

t, days

Figure 10. Correlation of maximum plant N concentration (N) with time after planting (t) for corn at Quincy,
Florida (1978). Line drawn from Equation (9).


















3 -






2

E












0 I I
0 20 40 60 80 100 120

t, days

Figure 11. Dependence of maximum plant N concentration (Nm) on time after planting (t) for corn at Quincy,
Florida (1978). Curve drawn from Equation (10).





















































1 2 3 4 5 6


Applied N,


g/plant


Figure 12. Response of plant N concentration to applied N, plant population, and time after planting for corn at
Quincy, Florida (1978). Curves drawn from Equation (10).














90,000 plants/ha


Symbol t. days


60.000 plants/ha


1.2


Applied P,


9/plant


Figure 13. Dependence of plant P concentration oh applied P, plant population, and time after planting for corn at
Quincy, Florida (1978).


1.6


I


__


.1




0
































O0
o4-)
0
L
-P
C
0 --- I -
o 0
0
C
0





0










.1 -





0 I ii
0 .4 .8 1.2 1.6 2


Applied P. g/plant

Figure 14. Dependence of plant P concentration on applied P and plant population at 91 Days after planting for
corn at Quincy, Florida (1978).



























O d

UI











.01 I I 0 I
0 20 40 60 80 100


t, days


Figure 15. Correlation of plant P concentration (PC) with time after planting (t) for corn at Quincy, Florida (1978).
Line drawn from Equation (11).

















.4







x
.2









0.0 I
0 20 40 60 80 100 120

t. days


Figure 16. Dependence of plant P concentration (P.) on time after planting (t) for corn at Quincy, Florida (1978).
Curve drawn from Equation (11).













90,000 plants/ha













SSymbol t. days
S 1L o 42
Sx 54
L 70
-P # 91
C
0




C
#-----------------------














0 1 2 3 4 5

Applied K. g/plant


Figure 17. Dependence of plant K concentration on applied K, plant population, and time after planting for corn at
Quincy, Florida (1978).




28
1















90.000 plants/ha


60,000 plants/ha


Applied K.


9/plant


Figure 18. Dependence of plant K concentration on applied K and plant population at 91 Days after planting for
corn at Quincy, Florida (1978)


I 1 I I


I I


t = 91 days


E ......











10
9
8

7

6

5


40 0


N
3





2

0








0 20 40 60 80 100 120


t, days


Figure 19. Correlation of plant K concentration (Ks) with time after planting (t) for corn at Quincy, Florida (1978).
Line drawn from Equation (12).











'(i L) uollenb3 wo.4 uMsJp eAuno
'(8L6 L.) eplJOl| 'Aoulno )e uoo Jo (1) Bu|{ueld JeUll eail uo ()) uoflDJiueouoo ) lueld 0o eouopuadaG "0o enBl

sXop 'i,


O0r 001 08 09 0 02 0













00













Dry Matter,


g/plant





o


N Concentration,


% N Uptake, g/plant


0



0.



0


r-
0








C,







0
on
5.






om


E.0
U=







CL
-*'
















o
0
z
-0

















01
a 2
en


g ^ 90.000 plants/ha





0
+ t = 100 days
z3










4-P
C
0


a
L






z


C
0
-P
c
00



200
C-



-P 100

0
Cr

0 L
0 1 2 3 4 5 6


Applied N, 9/plant


Figure 22. Estimated Response of dry matter, plant N concentration, and plant N removal to applied N at 100
Days after planting for corn at Quincy, Florida. Curves drawn from Equations (4), (6), and (11).























































































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age, sex, or handicap. Printed 10/91. ISSN 0096-607X




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