Four-Year Rotations with Wheat and Grain Sorghum
A. Schlegel, T. Dumler, J. Holman, and C. Thompson
Introduction
In recent years, cropping intensity has increased in dryland systems in western Kansas. The traditional wheat-fallow system is being replaced by wheat-summer crop-fallow rotations. With concurrent increases in no-till, is more intensive cropping feasible? Objectives of this research were to quantify soil water storage, crop water use and crop productivity of 4-year and continuous cropping systems.
Alan Schegel - Tribune, Kansas
Summary
Research on 4-year crop rotations with wheat and grain sorghum was initiated at the Southwest Research-Extension Center near Tribune, KS, in 1996. Rotations were wheat-wheat-sorghum-fallow (WWSF), wheat-sorghum-sorghum-fallow (WSSF), and continuous wheat (WW). Soil water at wheat planting averaged about 9 in. following sorghum, which is about 3 in. more than that for the second wheat crop in a WWSF rotation. Soil water at sorghum planting was approximately 1.2 in. less for the second sorghum crop compared with sorghum following wheat. Grain yield of recrop wheat averaged about 80% of the yield of wheat following sorghum. Grain yield of continuous wheat averaged about 70% of the yield of wheat grown in a 4-year rotation following sorghum. In most years, recrop wheat and continuous wheat yielded similarly. In 2009, however, recrop wheat yielded more than wheat following sorghum. Wheat yields were similar following one or two sorghum crops. Average sorghum yields also were the same following one or two wheat crops. Yield of the second sorghum crop in a WSSF rotation averaged about 70% of the yield of the first sorghum crop.