Automated Calibration Stamp Technology for Improved InSeason Nitrogen Fertilization

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Automated Calibration Stamp Technology for
Improved In-Season Nitrogen Fertilization

• K. Freeman, R. Teal, C. Mack, K. Martin, B.
  Arnall, K. Desta, J. Solie, M. Stone, H. Zhang,
  B. Raun

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Review

• Pre-sidedress nitrate test (PSNT) was an
  extension of preplant nitrate tests, in-season
  soil nitrate analysis was used to refine topdress
  rates (Bundy and Andraski, 1995).
• Predicting N mineralized from soil organic matter
  could lead to improved N fertilizer
  recommendations (Cabrera and Kissel, 1988).
• Mulvaney et al. (2001) found that the
  concentration of amino sugar N was highly
  correlated with check-plot yields and fertilizer
  N response.
• Temporal variability strongly influences N
  supplied by soil organic matter and the demand
  for in-season N

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Review (cont)

• In many states, 33 kg N ha-1 is recommended for
  every 1 Mg of anticipated wheat yield (2 lb N
  ac-1 for every bushel of expected wheat grain
  yield)
• This strategy explicitly places the risk of
  predicting the environment (good or bad year) on
  the farmer
• Varvel et al. (1997) employed chlorophyll meter
  readings to calculate a sufficiency index
  in-season N fertilizer applications were made
  when index values were below 95.
• Sufficiency index lt 90 at the V8 growth stage in
  corn, maximum yields could not be achieved with
  in-season N fertilizer applications (Varvel,
  1997).

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Review

• Normalized difference vegetation index (NDVI)
  divided by the number of days from planting to
  sensing used to predict mid-season winter wheat
  yield potential (OSU)
• Response Index N Rich Strip (sufficient nitrogen
  but not excess) strip and the adjacent area with
  the field rate of preplant applied N.
• Although systems have been developed to determine
  midseason N fertilizer topdress recommendations,
  the need exists for a simple system that cereal
  grain producers can use to quickly estimate
  required N topdress rates.

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Response Indexvariable from year to year in the
same field
2004 RI 1.7
1995 RI 1.2
Long term N-P-K Experiments(1969-2004) Dr. Billy
Tucker
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Response to Fertilizer NLong-Term Wheat
ExperimentLahoma, OK 1970-2003
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Response to Fertilizer N
Response to Fertilizer N
Long-Term Corn Experiment
Mead, NE, 1969
-
1983
Mead, NE, 1969
-
1983
Prof. R.A. Olson
Prof. R.A. Olson
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Materials and Methods

• 2003 Honda FourTrax Foreman ES 4-wheeler (433-cc,
  127-cm wheel base, 116-cm wide) with a 3-m wide
  spray boom and a 1-m spacing between nozzles
• Modified to deliver a range of fixed N rates as
  urea ammonium nitrate (28 N) within a 9-m2 grid.
  
• 9 separate 1-m2 areas
• Four corners receive no fertilizer N.
• Rates of 22, 45, 67, 90, and 112 kg N ha-1 occupy
  the other 5

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CalibrationStamp
10
lb N / acre
80
0
0
20
100
60
0
40
0
Blue Dye, 30 ml L-1
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Pumpless pressurized spray system19L auxiliary
air tank11.3L Spartanburg stainless steel
tankProgrammable logic controllerRemcor
solenoid valves
Automated Calibration Stamp
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Winter WheatCalibration Stamp applied in
DecemberVisual Interpretation in March
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• Topdress N rate prescribed by choosing the lowest
  N rate where no visual differences were observed
  between it and the highest rate.

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December
CalibrationStamp
March
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Results

• Field-specific topdress N rate prescribed by
  choosing the lowest N rate where no visual
  differences were observed between it and the
  highest rate.
• N Rate NDVI N Rate NDVI N Rate NDVI
• 100 0.80 100 0.76 100 0.69
• 80 0.79 80 0.74 80 0.68
• 60 0.78 60 0.68 60 0.69
• 40 0.65 40 0.55 40 0.67
• 20 0.55 20 0.45 20 0.68
• 0 0.51 0 0.41 0 0.54

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http//www.soiltesting.okstate.edu/SBNRC/SBNRC.php

www.nue.okstate.edu
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(No Transcript)
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N Rich Strip (J. Lawles, S. Reed)NTech
Industrieswww.ntechindustries.com
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Summary

• Calibration stamps applied preplant or soon after
  planting assist in providing visual
  interpretation of N mineralization atmospheric
  N deposition from planting to the time mid-season
  N is applied, and improved determination of
  topdress N rates.
• Cost Honda 4X 5000Tanks, Controller,
  Nozzles, Valves, Boom, Programming, Labor 800
• Can be used with on-line Sensor Based N Rate
  Calculator to improve mid-season N management

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GreenSeeker-Red
Average NDVI 0.816, standard deviation in NDVI
0.0056 Distance to target 0.8-1.2m
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gt15 readings 0.4m2 /- 0.005