PRECISION SIDEDRESS UAN APPLICATION FOR CORN PRODUCTION

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PRECISION SIDEDRESS UAN APPLICATION FOR CORN
PRODUCTION
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• Kefyalew Girma
• Oklahoma State University

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Introduction
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Nitrogen Leak
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Introduction
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Coulter UAN application in corn (Ames, IA). UAN
surface application is made within the center of
the row, 15 inches away from the base of each
stalk.
The common use of UAN for sidedress N
application in corn is to apply this liquid
fertilizer in the middle of rows using either
dribble surface bands, or rolling coulter
injection.
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Introduction
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Excavated corn plants showing no overlapping of
nodal root systems when corn plants were more
than 10 apart, at silking growth stage
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Objective

• to compare three sidedress N placement methods on
  corn grain yield/where
• Evaluate sidedress N rates

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Sense by plant and treat based on yield potential
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Treatment structure of precision sidedress UAN
experiment, Haskell and Lake Carl Blackwell,
2005-2006.
Trt Pre Side d. Placement method
1 40 20 Directed stream application at the base of each plant (1)
2 40 20 Directed stream application at the base of a row (2)
3 40 20 Dribble surface bands applied in the middle of two rows (3)
4 40 40 1
5 40 40 2
6 40 40 3
7 40 80 1
8 40 80 2
9 40 80 3
10 40 160 1
11 40 160 2
12 40 160 3
13 0 0 NA
14 40 0 Broadcast
15 200 0 Broadcast
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By-row
By-plant
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Between rows
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Directed Stream Applicator
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Directed stream application of UAN in corn
applied at the base of stalk of the plant
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Design and Field Layout
Location Haskell-2005
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• Plot size 10 x 20 with 5 alley
• By plant N rate was determined as
• Calculate UAN/row
• Divide the above by number of plants/row

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Between row and within row by plant corn grain
weight variability at Haskell (Hask) and Lake
Carl Blackwell (LC), OK, 2005.
Row Mean dry grain weight, lb/plant Mean dry grain weight, lb/plant Mean dry grain weight, lb/plant Percent of no. of plants with yield gt mean Percent of no. of plants with yield gt mean Range, lb/plant Range, lb/plant Range, lb/plant Standard deviation lb/plant Standard deviation lb/plant
Row Hask Hask LC Hask LC Haskl Haskl LC Hask LC
1 0.20 0.38 0.38 50 53 0.31 0.35 0.35 0.09 0.09
2 0.19 0.38 0.38 50 47 0.34 0.35 0.35 0.09 0.09
Pro ns ns ns ns ns ns ns ns ns ns
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Between row and within row by plant corn grain
weight variability at Haskell (Hask) and Lake
Carl Blackwell (LC), OK, 2006.
Row Mean dry grain weight, lb/plant Mean dry grain weight, lb/plant Mean dry grain weight, lb/plant Percent of no. of plants with yield gt mean Percent of no. of plants with yield gt mean Range, lb/plant Range, lb/plant Standard deviation lb/plant Standard deviation lb/plant
Row Hask Hask LC Haskl LC Hask LC Hask LC
1 0.21 0.20 0.20 45 41 0.41 0.53 0.12 0.11
2 0.21 0.19 0.19 46 40 0.43 0.55 0.13 0.12
Pro ns ns ns ns ns ns ns ns ns
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Martin et al. (2005) Agron. J. 971603-1611
Regardless of yield level, plant-to-plant
variability in corn grain yield can be expected
and averaged more than 2765 kg ha-1 (44 bu/ac)
over 46 sites (Ohio, Iowa, Nebraska, Virginia,
Mexico, Argentina)
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Effect of UAN sidedress placement method on corn
grain yield
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Effect of sidedress N rates on corn grain yield
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Summary

• Within row variability in grain yield was very
  high
• By plant sidedress application of N according to
  individual plant yield potential would result in
  improved efficiency and reduced cost to producers
  
• The gain in yields from the three methods ranged
  from 7 to 25 more than the broadcast treatment
  in three location-years

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Summary

• Under normal growing conditions, N should be
  sidedressed by plant at a rate of 20-40 lb/A to
  maintain yield level and decrease loss in
  fertilizer N concurrent with within row plant to
  plant variability
• Results are not conclusive as the 2006 corn
  growing season was extremely dry/hot
• The experiment will be continued for 1 more year

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Summary

• Additional measurements such as ears per plant,
  100-seed weight, ear size, plant spacing, and
  grain N concentration

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THANK YOU!
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