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

A four crop/three-year cropping system consists of no-till soybeans in corn stubble, followed by minimum till wheat, no-till soybeans, and then no-till corn the third year. The goal of this study is to develop a management program that increases crop yield level, input efficiency, and profit potential in such a system.

In the first year, the rotation improved corn yield by 14 bu/A and soybean yield by 5 bu/A. Specifically, full season soybeans in the new rotation yielded 37 bu/A, while corn yielded 174 bu/A. The conventional corn/soybean rotation yielded 144 bu/A of corn.

A record yield of wheat was harvested during 1997, 151 bu/A, compared with the Maryland state average of 60, the highest farmer yield of 85, and the highest previous research yield of 125 bu/A.

In 1999, as in 1995-97, the top corn grain yields resulted from no-till corn in various rotation patterns with wheat and soybeans. Grain yields ranged from 151 to 158 bu/A. The goals for hard red winter wheat are 100 bu/A. with a good test weight and protein levels above 13 percent.

The 2000 growing season was ideal from planting through harvest. When (NH₄)₂SO₄ was blended with urea, N use efficiency was improved. Corn yield improved from 30 bu/A without fertilizer N to 153 bu/A for the blend and 142 bu/A when the same rate of N was applied as NH₄NO₃. With adequate N, little difference in yield was noted for corn planted in 20- or 30-inch rows. MD-06F