Evaluation of Fertilizer Nitrogen Applications With and Without Ammonium Sulfate in Selected Vegetable Crops
IPNI-1999-USA-MD11
14 May 2001
2000 Annual Interpretive Summary
Evaluation of Fertilizer Nitrogen Applications with and without Ammonium Sulfate in Selected Vegetable Crops, 2000
The objective of this study is to measure the influence of (NH4)2SO4 blended with NH4NO3 on the yield of various vegetable crops.
In 1999 sweet corn yields increased from 1.6 to 6.5 tons/A in response to 120 lb N/A. Yields trended upward as the N rate increased to 200 lb/A. Little difference was noted between the no-till and minimum tillage treatments. During the 2000 season, the no-till sweet corn yielded 8.4 tons/A when 212 lb N/A was applied. Under minimum tillage, sweet corn yields topped out at 7.1 tons/A and response to N reached a plateau at 107 lb/A. When a blend of (NH4)2SO4 / NH4NO3 was compared with NH4NO3 alone (each at 160 lb N/A) the yield of sweet corn was 7.6 and 7.2 tons/A, respectively. Yield was increased to 8.3 tons/A when some of the (NH4)2SO4 was applied at row closure. The apparent response at row closure will be studied further in 2001. MD-11F