Effects of Wheat-Residue Management on Double-Cropped Soybean and Subsequent Crops

Abstract

Management of wheat (Triticum aestivum L.) residue is an important consideration in production of double-cropped soybean [Glycine max (L.) Merr.]; however, little information is available concerning long-term effects of wheat-residue management on subsequent crop yield and soil quality. A 12-yr study was conducted in southeastern Kansas to evaluate the agronomic effects of three wheat-residue management practices (moldboard plow, burn then disk, and disk only) on: (i) grain yield, seed weight, and leaf nutrient concentrations (N,P,K) of double-cropped and full-season soybean and winter wheat in a 2-yr cropping rotation; (ii) soil moisture and bulk density at the R5 soybean growth stage; and (iii) changes in soil fertility properties (pH, organic matter [OM], P, and K). Double-cropped soybean yield varied with wheat-residue management and available soil moisture, but no residue practice was superior in all years. Seed weight and leaf K concentration of double-cropped soybean were highest with plowing, whereas disking resulted in greater soil bulk density, regardless of year. Grain yield, seed weight, and leaf N, P, and K concentrations of subsequent full-season soybean and winter wheat were not affected significantly by previous wheat residue management. After six 2-yr cropping cycles, soil pH, OM, available P, and exchangeable K had changed very little from initial values. In rotations where double-cropping occurs only once every 2 or 3 yr, wheat-residue management may not have significant long-term effects on subsequent crop yield or soil quality.