Locations Efaw
Lake Carl BlackwellHaskell
Years2005, 2006
Objectives:
1)To determine the minimum preplant N fertilizerneeded to achieve maximum yield if sidedress Nfertilizer is applied later in the season.
2) To determine how late sidedress N can be appliedwithout decreasing grain yields.
Effect of Delayed Nitrogen FertilizationEffect of Delayed Nitrogen Fertilization
on Corn Grain Yieldson Corn Grain Yields
Treatment
Preplant N fertilizerapplication
Sidedress N fertilizer application
N rate (kg ha -1)
N rate (kg ha -1)
Growth stage
1
0
0
-
2
90
0
-
3
180
0
-
4
0
90
V6
5
0
180
V6
6
0
90
V10
7
0
180
V10
8
0
90
VT
9
0
180
VT
10
90
90
V6
11
90
90
V10
12
90
90
VT
13
45
45
V10
14
45
45
V6
Grain yield as a function of N application timingGrain yield as a function of N application timing
LCB, 2005
SED = 0.6
Grain yield as a function of N application timingGrain yield as a function of N application timing
LCB, 2006
SED = 2.0
NUE as a function of N application timingNUE as a function of N application timing
LCB, 2005
NUE as a function of N application timingNUE as a function of N application timing
LCB, 2006
ConclusionsConclusions
Grain yields decreased when noGrain yields decreased when no
preplant N was applied and sidedress N waspreplant N was applied and sidedress N was
delayed until VTdelayed until VT
Recommend preplant N followedRecommend preplant N followed
by N application at or before V10.by N application at or before V10.
Window of opportunity for mid-seasonWindow of opportunity for mid-season
N application: V6 – V10.N application: V6 – V10.
Grain yields decreased when noGrain yields decreased when no
preplant N was applied and sidedress N waspreplant N was applied and sidedress N was
delayed until VTdelayed until VT
Recommend preplant N followedRecommend preplant N followed
by N application at or before V10.by N application at or before V10.
Window of opportunity for mid-seasonWindow of opportunity for mid-season
N application: V6 – V10.N application: V6 – V10.
Location Lake Carl Blackwell
Years2006
Objectives:
1) To establish the amount of nitrogen accumulated
in corn over the entire growing season under
different levels of N fertilizer.
Aboveground N Accumulation as
Function of Time in Corn
Nitrogen Uptake of Corn at Different GrowthStages at Lake Carl Blackwell, 2006.Nitrogen Uptake of Corn at Different GrowthStages at Lake Carl Blackwell, 2006.
SummarySummary
Maximum N uptake occurred at growthstages V12 from treatments receiving Nfertilizer.Maximum N uptake occurred at growthstages V12 from treatments receiving Nfertilizer.
N uptake continued to increase until VT inplots receiving no fertilizer N.N uptake continued to increase until VT inplots receiving no fertilizer N.
Maximum N uptake occurred at growthstages V12 from treatments receiving Nfertilizer.Maximum N uptake occurred at growthstages V12 from treatments receiving Nfertilizer.
N uptake continued to increase until VT inplots receiving no fertilizer N.N uptake continued to increase until VT inplots receiving no fertilizer N.
Locations Lake Carl Blackwell
Efaw
Years2005, 2006
Objectives:
1) To determine corn grain yield reduction as a
function of interplant competition arising from
delayed emergence.
2) To evaluate yield levels associated with 3plant sequences, with and without delayed
emergence.
Effect of Delayed Emergence on Corn
Grain Yields
TreatmentTreatment
Delay in plantingDelay in planting
N rate, kgha-1N rate, kgha-1
11
All 3 plants planted on the same dayAll 3 plants planted on the same day
00
22
All 3 plants planted on the same dayAll 3 plants planted on the same day
5656
33
Middle plant planted 2 days lateMiddle plant planted 2 days late
5656
44
Middle plant planted 5 days lateMiddle plant planted 5 days late
5656
55
Middle plant planted 8 days lateMiddle plant planted 8 days late
5656
66
Middle plant planted 12 days lateMiddle plant planted 12 days late
5656
77
All 3 plants planted on the same dayAll 3 plants planted on the same day
168168
88
Middle plant planted 2 days lateMiddle plant planted 2 days late
168168
99
Middle plant planted 5 days lateMiddle plant planted 5 days late
168168
1010
Middle plant planted 8 days lateMiddle plant planted 8 days late
168168
1111
Middle plant planted 12 days lateMiddle plant planted 12 days late
168168
XXX
XOX
XXX
XXX
XOX
XXX
XXX
XOX
XXX
XXX
XOX
XXX
XXX
XOX
XXX
X O X
X O X
ConclusionsConclusions
Delayed emergence reduces corn grain yieldsDelayed emergence reduces corn grain yields
Greater than 5 days delay - significant yieldreduction (homogeneity of plant stands)Greater than 5 days delay - significant yieldreduction (homogeneity of plant stands)
There was a linear reduction in yield with eachday of delayed plantingThere was a linear reduction in yield with eachday of delayed planting
Plants delayed by 2,5, and 8 days continued tocompete with border plants. By 12 daysthese plants competed less with borderplants.Plants delayed by 2,5, and 8 days continued tocompete with border plants. By 12 daysthese plants competed less with borderplants.
Delayed emergence reduces corn grain yieldsDelayed emergence reduces corn grain yields
Greater than 5 days delay - significant yieldreduction (homogeneity of plant stands)Greater than 5 days delay - significant yieldreduction (homogeneity of plant stands)
There was a linear reduction in yield with eachday of delayed plantingThere was a linear reduction in yield with eachday of delayed planting
Plants delayed by 2,5, and 8 days continued tocompete with border plants. By 12 daysthese plants competed less with borderplants.Plants delayed by 2,5, and 8 days continued tocompete with border plants. By 12 daysthese plants competed less with borderplants.
Effect of Altered Nitrogen Distribution onCorn Grain YieldEffect of Altered Nitrogen Distribution onCorn Grain Yield
LocationsLake Carl Blackwell
Efaw
Years2005, 2006
Objectives
To determine the application resolution at whichN competition influences corn grain yield 1) To determine the application resolution at whichN competition influences corn grain yield
2)To determine the N application resolution atwhich corn grain yields are maximized. 2)To determine the N application resolution atwhich corn grain yields are maximized.
Treatment StructureTreatment Structure
Trt
Plant Distance
(cm)
Preplant N
kg ha-1
Sidedress* N Distribution
Application Scenario
1
18
0
Check, 0 Preplant and Sidedress N
2
18
45
By-plant
3
18
45
Every 2 plants
4
18
45
Every 3 plants
5
18
45
Middle of the row
6
18
45
Distributed in the entire row
7
18
45
Check, 0 Sidedress N
8
11
0
Check, 0 Preplant and Sidedress N
9
11
45
By-plant
10
11
45
Every 2 plants
11
11
45
Every 3 plants
12
11
45
Middle of the row
13
11
45
Distributed in the entire row
14
11
0
Check, 0 Sidedress N
* 62 kg ha-1 for dryland and 123 kg ha-1 for irrigated
Sidedress N Distribution
Scenarios
Distributed in the Entire RowDistributed in the Entire Row
Center PlantCenter Plant
of the Rowof the Row
By-PlantBy-Plant
Grain Yield at LCB, 2005 and 2006Grain Yield at LCB, 2005 and 2006
Trt
Distance,
cm
Scenario
Total N Appiled
Kg ha-1
Grain Yield, Mg ha-1
2005
2006
1
18
-
0
12.9
4.0
2
18
By-plant
168
15.0
7.2
3
18
Every 2 plants
168
.
4.3
4
18
Every 3 plants
168
15.2
4.6
5
18
Middle row
168
15.1
5.5
6
18
Distributed
168
13.5
8.2
7
18
-
45
12.9
5.6
8
28
-
0
16.1
3.8
9
28
By-plant
168
16.2
5.5
10
28
Every 2 plants
168
.
6.7
11
28
Every 3 plants
168
18.8
5.5
12
28
Middle row
168
15.3
4.4
13
28
Distributed
168
15.6
4.0
14
28
-
45
15.5
5.4
Grain Yield at Efaw, 2005 and 2006Grain Yield at Efaw, 2005 and 2006
Trt
Distance,
cm
Scenario
Total N Appiled
Kg ha-1
Grain Yield, Mg ha-1
2005
2006
1
18
-
0
3.1
4.7
2
18
By-plant
107
8.3
6.1
3
18
Every 2 plants
107
.
8.8
4
18
Every 3 plants
107
8.8
9.5
5
18
Middle row
107
8.2
9.2
6
18
Distributed
107
10.0
9.8
7
18
-
45
5.0
6.1
8
28
-
0
3.3
4.2
9
28
By-plant
107
7.8
8.4
10
28
Every 2 plants
107
6.9
8.2
11
28
Every 3 plants
107
7.8
9.5
12
28
Middle row
107
6.0
7.3
13
28
Distributed
107
7.4
9.3
14
28
-
45
5.2
5.7
Evaluating Nitrogen Competition AcrossRows in CornEvaluating Nitrogen Competition AcrossRows in Corn
LocationsLake Carl Blackwell
Years2005, 2006
Objective
To evaluate alternate row N placementon corn grain yield.
Treatment StructureTreatment Structure
Trt
Sidedress N Applied kg ha-1
Row Sequence (1-2-3-4-5)
1
134-134-134-0-0
2
100-100-100-0-0
3
67-67-67-0-0
4
34-34-34-0-0
5
134-134-0-0-0
6
134-134-34-0-0
7
134-134-67-0-0
8
0-0-67-0-0
9
0-0-0-0-0
10
134-134-134-134-134
11
134-134-0-134-0
Grain Yield, 2005 and 2006Grain Yield, 2005 and 2006
Trt
Sidedress N Applied kg ha-1
Row Sequence (1-2-3-4-5)
Grain Yield, Mg ha-1
2005 2006
1
134-134-134-0-0
9.5
5.7
2
100-100-100-0-0
9.1
4.5
3
67-67-67-0-0
9.2
4.1
4
34-34-34-0-0
8.2
3.0
5
134-134-0-0-0
9.0
3.3
6
134-134-34-0-0
10.5
4.0
7
134-134-67-0-0
9.3
5.7
8
0-0-67-0-0
6.6
4.7
9
0-0-0-0-0
7.7
4.5
10
134-134-134-134-134
10.8
5.6
11
134-134-0-134-0
10.8
5.2
Figure 1. Grain yield of corn plants where sidedress N fertilizer was applied
in the first 3 rows only, 2005.
First 3 Rows Fertilized
Last 2, 0-N
Figure 2. Grain yield of corn plants where sidedress N fertilizer was applied
in the first 3 rows only, 2006.
First 3 Rows Fertilized
Last 2 Rows, 0-N
Effect of Nitrogen Fertilizer Rate andPlacement on Corn Grain YieldEffect of Nitrogen Fertilizer Rate andPlacement on Corn Grain Yield
LocationsLake Carl Blackwell
Haskell
Year2006
Objectives
1) To evaluate the use of directed stream application at
the base of the plant using UAN versus dribble
surface bands applied in the middle of the row.
2) To evaluate the use of directed stream application at
the base of the plant, and by-plant using UAN versus
dribble surface bands applied in the middle of the row.
Treatment StructureTreatment Structure
Trt
Pre-plant
kg ha-1
Sidedress (V8-V10)
kg ha-1
Method
1
40
20
By plant at base
2
40
20
By row at base
3
40
20
DSB at center
4
40
40
By plant at base
5
40
40
By row at base
6
40
40
DSB at center
7
40
80
By plant at base
8
40
80
By row at base
9
40
80
DSB at center
10
40
160
By plant at base
11
40
160
By row at base
12
40
160
DSB at center
13
0
0
-
14
40
0
-
15
200
0
-
Corn grain yield at LCB and Haskell, 2005 and 2006Corn grain yield at LCB and Haskell, 2005 and 2006
Trt
Total N Applied
kg ha-1
Method
Grain Yield, Mg ha-1
Lake Carl Blackwell
2005 2006
Haskell
2005 2006
1
60
By plant at base
9.2
4.8
4.1
2.9
2
60
By row at base
9.8
4.2
3.8
3.3
3
60
DSB at center
9.7
5.1
3.6
3.2
4
80
By plant at base
10.2
5.0
3.8
3.6
5
80
By row at base
10.2
4.5
3.6
3.0
6
80
DSB at center
10
5.2
3.6
3.1
7
120
By plant at base
9.8
4.4
3.5
2.8
8
120
By row at base
10.1
4.4
3
3.5
9
120
DSB at center
10
4.4
3.6
3.5
10
200
By plant at base
9.4
4.0
3.6
2.7
11
200
By row at base
9.2
4.0
3.8
3.1
12
200
DSB at center
9.8
5.2
3.4
3.1
13
0
-
9
2.7
2.9
3.2
14
40
-
10.1
3.9
3.5
2.8
15
200
-
10.7
3.6
3.2
2.4
Corn NUE% at LCB and Haskell, 2005 and 2006.Corn NUE% at LCB and Haskell, 2005 and 2006.
Trt
Total N Applied
kg ha-1
Method
Grain NUE%
Lake Carl Blackwell
2005 2006
Haskell
2005 2006
1
60
By plant at base
5
38
25
0
2
60
By row at base
18
27
17
2
3
60
DSB at center
16
44
14
0
4
80
By plant at base
20
32
15
5
5
80
By row at base
19
25
11
0
6
80
DSB at center
17
35
11
0
7
120
By plant at base
10
15
7
0
8
120
By row at base
12
16
0
3
9
120
DSB at center
11
16
6
3
10
200
By plant at base
3
7
5
0
11
200
By row at base
2
7
5
0
12
200
DSB at center
5
14
3
0
13
0
-
-
-
-
-
14
40
-
34
33
19
0
15
200
-
11
5
2
0
CORN OFITCORN OFIT
LocationsLake Carl Blackwell
Efaw
Perkins
Year2004, 2005, 2006
Objectives
1) To determine the nitrogen fertilization optimization
algorithm that will be used to estimate N rate for
optimum corn growth.
2) To determine optimum resolution to treat field spatial
variability in corn.
Treatment StructureTreatment Structure
TRTTRT
Preplant NPreplant N
kg ha-1kg ha-1
Mid-Season SidedressRate kg ha-1Mid-Season SidedressRate kg ha-1
ResolutionResolution
m2m2
11
00
00
--
22
00
6767
--
33
00
134134
--
44
6767
6767
--
55
6767
00
--
66
134134
00
--
77
00
RICV- NFOARICV- NFOA
0.340.34
88
6767
RICV-NFOARICV-NFOA
0.340.34
99
00
Flat RICV-NFOAFlat RICV-NFOA
--
1010
6767
Flat RICV-NFOAFlat RICV-NFOA
--
1111
6767
RICV-NFOARICV-NFOA
2.322.32
1212
00
RI-NFOARI-NFOA
0.340.34
1313
6767
RI-NFOARI-NFOA
0.340.34
ResultsResults
TreatmentTreatment
PreplantPreplant
kg ha-1kg ha-1
SidedressSidedress
kg ha-1kg ha-1
Grain YieldGrain Yield
Mg ha-1Mg ha-1
Nitrogen UseEfficiencyNitrogen UseEfficiency
%%
20042004
20052005
20062006
20042004
20052005
20062006
20042004
20052005
20062006
CheckCheck
00
00
00
00
9.59.5
6.26.2
5.65.6
--
--
--
Common FlatRateCommon FlatRate
6767
6767
6767
6767
13.413.4
10.310.3
9.69.6
4848
5757
3838
67-RICV67-RICV
6767
2525
127127
5252
13.913.9
12.012.0
11.111.1
3131
5252
5757
67-RICV flat67-RICV flat
6767
2525
127127
5252
13.313.3
11.511.5
10.310.3
3535
4949
4848
67-RI67-RI
6767
1313
6666
2424
14.014.0
12.412.4
11.911.9
7777
7474
7979
Common Flat Rate versus Algorithms at Efaw site from 2004-2006
With Preplant Nitrogen
ResultsResults
TreatmentTreatment
SidedressSidedress
kg ha-1kg ha-1
Grain YieldGrain Yield
Mg ha-1Mg ha-1
Nitrogen UseEfficiencyNitrogen UseEfficiency
%%
20042004
20052005
20062006
20042004
20052005
20062006
20042004
20052005
20062006
CheckCheck
00
00
00
9.59.5
6.26.2
5.65.6
--
--
--
Common FlatRateCommon FlatRate
6767
6767
6767
13.113.1
9.99.9
9.49.4
7171
6969
7373
Common FlatRateCommon FlatRate
134134
134134
134134
11.811.8
10.210.2
8.88.8
3535
4444
3434
0-RICV0-RICV
5959
100100
5858
11.211.2
8.68.6
6.96.9
3232
5050
3737
0-RICV flat0-RICV flat
5959
100100
5858
13.513.5
9.49.4
9.19.1
5050
5151
6767
0-RI0-RI
1717
6666
4848
12.912.9
10.110.1
9.29.2
7979
7373
8383
Common Flat Rates versus Algorithms at Efaw site from 2004-2006
Without Preplant Nitrogen
ResultsResults
AlgorithmAlgorithm
ResolutionResolution
m2m2
Total N AppliedTotal N Applied
Kg ha-1Kg ha-1
Grain YieldGrain Yield
Mg ha-1Mg ha-1
Nitrogen UseEfficiencyNitrogen UseEfficiency
%%
20042004
20052005
20062006
20042004
20052005
20062006
20042004
20052005
20062006
CheckCheck
--
00
00
00
9.59.5
6.26.2
5.65.6
--
--
--
RICV-NFOARICV-NFOA
0.340.34
2525
127127
5252
13.913.9
12.012.0
11.111.1
3131
5252
5757
RICV-NFOARICV-NFOA
flatflat
2525
127127
5252
13.313.3
11.511.5
10.310.3
3535
4949
4848
RICV-NFOARICV-NFOA
2.322.32
2525
132132
5656
13.313.3
11.411.4
10.110.1
3535
4646
5454
RI-NFOARI-NFOA
0.340.34
1313
6666
2424
14.014.0
12.412.4
11.911.9
7777
7474
7979
RICV- versus RI-NFOA at Efaw from 2004-2006.
With Preplant N
ResultsResults
TRT
Description
Total N Applied
kg ha-1
Grain Yield
Mg ha-1
NUE, %
1
Check
0
5.5
-
2
*CFR-topdress
67
8.2
59
3
*CFR-topdress
134
8.5
40
4
*CFR-split
134
9.3
48
5
*CFR-preplant
67
8.0
56
6
*CFR-preplant
134
9.1
44
7
RICV-NFOA
70
7.5
49
8
RICV-NFOA
131
9.1
43
9
Flat RICV-NFOA
70
7.8
51
10
Flat RICV-NFOA
131
8.9
42
11
RICV-NFOA-2.32
133
8.8
46
12
RI-NFOA
63
8.3
63
13
RI-NFOA
124
9.6
56
On-average
* CFR : Common Flat Rate
SummarySummary
NUE was generally higher when mid-season N rates were generated by NFOAcompared with flat farmer rates.NUE was generally higher when mid-season N rates were generated by NFOAcompared with flat farmer rates.
Increased NUE was attributed to thelower N rates applied.Increased NUE was attributed to thelower N rates applied.
NUE was generally higher when mid-season N rates were generated by NFOAcompared with flat farmer rates.NUE was generally higher when mid-season N rates were generated by NFOAcompared with flat farmer rates.
Increased NUE was attributed to thelower N rates applied.Increased NUE was attributed to thelower N rates applied.
SummarySummary
Use of RI NFOA resulted in a higherincrease in NUE than RICV NFOA.Use of RI NFOA resulted in a higherincrease in NUE than RICV NFOA.
There was limited benefit of treating spatialvariability at the high resolution (0.34 m2,RICV algorithm).There was limited benefit of treating spatialvariability at the high resolution (0.34 m2,RICV algorithm).
NFOA approaches didn’t project high Nrates that did not affect increased yields.NFOA approaches didn’t project high Nrates that did not affect increased yields.
Use of RI NFOA resulted in a higherincrease in NUE than RICV NFOA.Use of RI NFOA resulted in a higherincrease in NUE than RICV NFOA.
There was limited benefit of treating spatialvariability at the high resolution (0.34 m2,RICV algorithm).There was limited benefit of treating spatialvariability at the high resolution (0.34 m2,RICV algorithm).
NFOA approaches didn’t project high Nrates that did not affect increased yields.NFOA approaches didn’t project high Nrates that did not affect increased yields.