Evaluation of Ammonium Sulfate Nitrate in Virginia Sweet Corn Production


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