Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the EnvironmentVariable N Rate Applicator, Developed by Oklahoma State University

NDVI and CV collected from every 4 square feet and fertilized accordingly on-the-go

CV algorithm tested for variable N application in Winter WheatPress Release of the GREENSEEKER
See video of VRT applicator in the field (VIDEO
CV-Applicator, Video

OSU, Variable N Rate Applicator, employing the new CV algorithm (March 2005).
Manuscript documenting the CV Algorithm

Index Sensors (more pictures)

Hand Held Sensors

Variable N Rate Applicator Retrofitted by NTech Industries, and the Oklahoma State VRT Applicator near Cherokee, OK, February 2004

Variable N Rate Application near Red Rock, OK, March, 2004


Calibration accuracy resulted in small application error (below)
Application precision to within 6" evident in this slide for 4 separate sensor-nozzle units (below)
Faulty sensor assembly resulted in application error (3 feet).
Spatial variability in a poor stand of wheat, near Hennessey, OK, April 3, 2002 (below)
Earl Marshall Homeplace, April 3, 2002 (VRT rate = 30 lb N/ac)
Pictures from October 2001, Precision Sensing Day
Trimble Pocket Sensor, Greenseeker, NDVI, nitrogen