Early‐Maturing Soybean in a Wheat–Soybean Double‐Crop System Yield and Net Returns

Abstract

Double‐cropping soybean [ Glycine max (L.) Merr.] after harvesting wheat ( Triticum aestivum L.) is an important production system in the mid‐southern USA. Field studies were conducted at Stoneville, MS (33°26′ N lat) to evaluate the seed yield and net returns from early soybean maturity groups grown in a double‐crop system under limited irrigation and to compare the results with those from a full‐season system. Soybean cultivars from maturity groups (MG) III, IV, and V were used. Double‐cropped soybean yields ranged from 2055 to 3767 kg ha −1 and were 10 to 40% lower than their full‐season counterparts. For both systems, the average yield and net returns from MG IV, in particular the late IV cultivars, were among the highest, whereas those from MG III and late V were generally the lowest. The net returns from the full‐season soybean averaged $85 to 274 ha −1 higher than those from the double‐cropped soybean; however, the net returns from the double‐cropped wheat more than compensated for these differences. The 3‐yr average wheat yield was 5170 kg ha −1 and accounted for more than 60% of the combined net returns from the double‐crop system. These results indicate that yields and net returns from double‐cropped MG III or IV soybean could be equal or greater than MG V cultivars, but the late MG IV provided the highest yield and economic return. The data indicated that wheat–soybean double‐crop system using MG III or IV under limited irrigation was more profitable than the full‐season soybean system.