by-plant n management oklahoma state university
TRANSCRIPT
By-Plant N By-Plant N ManagementManagement
Oklahoma State University
Scale
Ames, IA
Ames, IA
Stillwater, OK
By-Plant N ManagementBy-Plant N Management
Paul Hodgen, Jim Schepers, 15N
60% of by-plant N accounted for in individual plants
Ames, IowaAmes, Iowa
0
1000
2000
3000
4000
5000
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7000
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9000
0 200 400 600 800 1000 1200 1400
Distance (cm)
Gra
in Y
ield
(kg
ha-1
)
Shelton, NE
Ames, IAAmes, IA
Agron. J. 97:1603-1611Agron. J. 97:1603-1611
At the sites with the highest average corn grain yield (11478 and 14383 kg ha-1, Parana Argentina, and Phillips, NE), average plant-to-plant variation in yield was 4211 kg ha-1 (67 bu ac-1) and 2926 kg/ha (47 bu ac-1), respectively. As average grain yields increased, so too did the standard deviation of the yields obtained within each row. This clearly indicates that by-plant variability can be expected in high and low yielding environments. Furthermore, the yield range (maximum corn grain yield minus the minimum corn grain yield per row) was found to increase with increasing yield level. This work shows that regardless of yield level, plant-to-plant variability in corn grain yield can be expected and averaged more than 2765 kg ha-1 over sites and years.
Causes for Delayed and uneven emergence •variable depth of planting •double seed drops •wheel compaction •seed geometry within the furrow •surface crusting •random soil clods •soil texture differences •variable distance between seeds •variable soil compaction around the seed •insect damage •moisture availability •variable surface residue •variable seed furrow closure •volunteer early season root pruning (disease, insect)
5-Plant Sequence5-Plant Sequence
pq-2 pq-1 pq Pq+1 Pq+2
2/)( 2
1
pqpq
pq
HtHt
Ht
2/)( 2
1
pqpq
pq
HtHt
Ht
2/
2/)(2/)( 2
1
2
1
pqpq
pq
pqpq
pq
pq
HtHt
Ht
HtHt
Ht
Ht
Cadj of the Plant in Question
FormulaFormula INSEYC D
GY adjest
Grain Yield = 15661 * GYest + 3367.2R2 =0.48
0
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15000
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45000
50000
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8GYest
Gra
in Y
ield
(kg h
a-1)
EFAW, OK (2004)
LCB, OK (2004)
Hennessey, OK (2004)
EFAW, OK (2005)
LCB, OK (2005)
Treatment StructureTreatment StructureTrt Pre-plant
kg ha-1 Top-dress (V8-V10)
kg ha-1
Method
1 45 22 By plant at base
2 45 22 By row at base
3 45 22 DSB at center
4 45 45 By plant at base
5 45 45 By row at base
6 45 45 DSB at center
7 45 90 By plant at base
8 45 90 By row at base
9 45 90 DSB at center
10 45 180 By plant at base
11 45 180 By row at base
12 45 180 DSB at center
13 0 0 -
14 45 0 Broadcast
15 225 0 Broadcast
Methods of placementMethods of placement
By-plant By-row
Between rows
LCB 2007
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0 67 90 135 225
N rate, kg N ha -1
Gra
in y
ield
, M
g h
a
-1
Check
Each plant
Each row
Between rows
SED = 1.15
Haskell 2005
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 67 90 135 225
N rate, kg N ha-1
Gra
in y
ield
, M
g h
a-1
Check
Each plant
Each row
Between rows
SED = 0.55
•By-plant fertilization method had slightly higher yields in five out of six site-years, especially at the low N rate. •In five of six site years the middle N rates of 67 and 90 kg N ha-1 showed grain yields as high as or higher than the 135 and 225 kg N ha-1 N rates.
ResultsResults