Three Alternative Nitrogen Management Strategies for Cereal Grain

Three Alternative Nitrogen Management Strategies for Cereal Grain Production Brian Arnall Plant and Soil Sciences Department Oklahoma State University

Introduction Scrutiny of Nitrogen Application Environmental impact Rise in Fuel and Nitrogen cost Temporal Variability What Nature Provides Unpredictable Variables

Response Index

N-Rich Strip The Nitrogen Rich Strip: – What is it? – When and Where can it be used? Ease of application Drive by visibility

N-Rich Strip Yes or No

N-Rich Strip Sensor Based Nitrogen Rate Calculator Using Sensor Data and the Nitrogen Fertilizer Optimization Algorithm, N-Rates are prescribed for that field and its condition.

Aug 16, 2002 Fertilizer Optimization Aug 28, 2002 Algorithm Nitrogen 1. Establish preplant N Rich Strip(NRS) 4. 2. NDVI (biomass) 3. Predict potential yield 5. need # of days from planting to (YP 0) sensing (INSEY = biomass prod. /day) 6. INSEY vs. Yld eqn. Determine Response Index (RI) =NDVI NRS/NDVIFarmer Predict potential grain yield with added N, YPN =(YP 0*RI) Fertilizer Rec = (grain N uptake YP N – grain N uptake YP 0/0. 7) CORN May Planting date June August NDVI (sensing date) March WHEAT RI YP 0 days from planting to sensing (GDD>0) November YPN June

Ramp Calibration Strip The Ramp Calibration Strip – 16 N rates 0 – 195 lb N ac-1 (can be adjusted for other crops) Rate Interval 10 ft (adjustable) Truck or ATV mounted

Ramp Calibration Strip Walk it off 0 N 195 N

Ramp Calibration Strip Sensor Based

Strip Alternatives

VRT Variable Rate N Application Resolution – Wheat. 4 m 2 – Corn By-Plant

VRT Equipment

VRT Equipment

Questions? For More Information www. nue. okstate. edu