Monday, 10 July 2006

Can Variable Rate Technology Using Active Sensors Work in Bermudagrass and Ryegrass Production?.

Jagadeesh Mosali1, Jeffrey B. Ball1, Kefyalew Girma2, Shawn L. Norton1, and W.R. Raun2. (1) The Noble Foundation, PO Box 2180, Ardmore, OK 73402-2180, (2) Oklahoma State University, 051 Agricultural Hall Department of Plant and Soil Sciences, Oklahoma State Univeristy, Stillwater, OK 74078

Nitrogen(N) fertilizer recommendations currently based on yield goal for forage production in bermudagrass and ryegrass without considering the temporal and spatial variations in soil to supply N. Current study is taken up to develop a nitrogen fertilizer optimization algorithm using in-season spectral measurements collected in early growth phase. Reflectance measurements are taken to calculate Normalized Difference Vegetative Index (NDVI)) were taken using a GreenSeeker Hand Held optical reflectance sensor (NTech industries, Ukiah, CA). In-Season Estimate of Yield (INSEY) which is NDVI taken in-season divided by growing degree days is correlated with the N uptake at harvest and an algorithm was developed to predict the fertilizer that is needed by the crop for that particular harvest. This work has the potential to increase the N uptake and increase the NUE and decrease the environmental concerns. This paper also talks about the concerns and problems with this technology.

Back to 1.5B Soil Sampling in Space and Time - Theater
Back to WCSS

Back to The 18th World Congress of Soil Science (July 9-15, 2006)