Tuesday, November 14, 2006 - 10:15 AM
191-9
Variable-rate N fertilization of wheat and corn in Virginia.
S.B. Phillips, W.E. Thomason, P.H. Davis, and H.S. Khurana. Virginia Tech, Eastern Shore AREC, Painter, VA 23420
Considerable small-plot research has evaluated sensor-based N fertilization of winter wheat and corn. However, little work has been done using commercial-scale equipment on large plots. The objective of this study was to evaluate the GreenSeeker RT200 for making sensor-based, variable-rate N applications to winter wheat and corn in Virginia. The studies were conducted at eighteen locations in the Coastal Plain of Virginia in 2005 and 2006. Plot size was 18 m wide by 90 to 150 m long. In-season N was applied to both crops using a Spra-Coupe applicator with an 18-m boom, which was equipped with a GreenSeeker RT200 variable-rate spray system. The experimental design was a RCB that included a variable N rate applications determined using the GreenSeeker, a standard N rate based on tissue tests for wheat and yield goals for corn, and a range of predetermined fixed N rates. Results presented will include grain yield and accuracy of GreenSeeker-based N rates.