Ahmad Khalilian1, Will Henderson1, Young Han1, and P. J. Wiatrak2. (1) Clemson University, Edisto Research & Education Center, 64 Research Rd., Blackville, SC 29817, (2) University of Florida, 155 Research Rd., Quincy, FL 32351
The objectives of this project is to: a)Develop an algorithm for variable-rate application of nitrogen in cotton production utilizing plant NDVI and soil electrical conductivity (EC) data; and b)Determine the effects of site-specific and uniform application of nitrogen on crop responses, chemical use, and yield. Tests were conducted in a production field near Blackville, SC. The test field was divided into management zones based on soil electrical conductivity (EC) data. Ramp Calibration Strips (N Rich Strips: 16 rates 0 to 150 lbs/acre) were established in each management zones. The following N-rate treatments were replicated 4 times in plots of each zone using a Randomized Complete Block design: Conventional method - 30 lb/ac preplant plus 60 lb/ac side dress (90 lb/ac total); and Five rates of N fertilizer including zero lb/acre (control).