Spring Wheat Yield Assessment Using Noaa Avhrr Data

A potential application of the normalized difference vegetation index (NDVI) is to monitor crop yields over large areas. The study concentrated on the spring Mheat areas of North Dakota and South Dakota for several years (1989-1992). The NOAA AVHRR data was carefully analyzed to minimize processing and sampling errors. Sums of biweekly NDVI county averages over an eight week period from heading to crop maturity (approximately, June 22 to August 16) were the independent variables in the linear regressions with spring wheat yields. Both single year and mUlti-year spectral regression models were developed for each state. spring wheat yield predictions -using both within year model and the multiple year models compared favorably with similar reported studies. The accuracies from this approach shows promise for forecasting yields at the Agricultural Statistics District (ASD) and state levels. NDVI remains a potentially useful parameter in an integrated crop model with other agrometeorological parameters to estimate yields at the county level.