Evaluation of Ammonium Sulfate Nitrate in Virginia Sweet Corn Production
IPNI-2009-USA-VA23
24 Feb 2010
2009 Annual Interpretive Summary
Virginia farmers grow over 3,000 acres of fresh market sweet corn. They are interested in exploring sources and rates to improve N use efficiency. This trial compared three N sources (urea-ammonium nitrate, ammonium nitrate, and ammonium sulfate-nitrate) at three rates. The first two N sources were compared with and without S, applied as gypsum, at a rate designed to supply the equivalent amount of S provided by ammonium sulfate-nitrate (65 lb/A).
The N sources increased marketable yields by 16 to 50% using optimum N rates ranging from 110 to 125 lb/A. Agronomic efficiency ranged from 11 to 35 lb of marketable yield increase per lb of N applied. Sulfur added as gypsum did not increase yields, but ammonium sulfate-nitrate produced higher yields than the other two N sources.
These first-year findings support N management decisions that optimize food yields while minimizing risk of water contamination by N on the sandy loam soils of the Chesapeake Bay watershed. VA-23F