Building a Maximum Yield Cropping System for Corn, Wheat and Double-cropped Soybeans

The goal of this study is to develop a management program that increases crop yield, input efficiency, and profit potential in a predominantly no-till cropping system. This cropping system consists of four crops in three years: no-till soybeans in corn stubble, followed by minimum till wheat double-cropped with no-till soybeans, and then no-till corn. The rotation has clearly improved corn and soybean yields compared to continuous cropping.

During 1997, a record yield of wheat was harvested, 151 bu/A compared to the Maryland state average of only 60 bu/A. In 2001, hard red winter wheat yielded up to 123 bu/A with over 13 percent protein, when fertilized with a combination of solid and foliar nitrogen (N) applications.

Starting in 2000, blends incorporating ammoinium sulfate [(NH₄)₂SO₄] as part of the N source have been tested for no-till corn. Nitrogen use efficiency has appeared to improve when (NH₄)₂SO₄ was blended into the N source, either urea or ammonium nitrate (NH₄NO₃). In 2001, yields were 10 bu/A higher with a blend of liquid (NH₄)₂SO₄ and urea ammonium nitrate (UAN) than with UAN alone. However, studies with varying proportions in the blend suggest that the maximum benefit is achieved with 14 to 21 lb N/A supplied as (NH₄)₂SO₄. Corn yielded 10 bu/A more with an NPKS starter and broadcast N combination, as compared to the same amount of nutrient broadcast. MD-06F