Long‐term Crop Rotation and Tillage Affects Wheat and Double‐crop Soybean and Selected Soil Properties

Field studies were conducted from 1996 through 2006 in southeastern Kansas to evaluate the influence of previous crop [corn, Zea maysL.; grain sorghum, Sorghum bicolor(L.); and soybean, Glycine max(L.) Merr.] and tillage system (conventional versus no‐till) on grain yield of hard red winter wheat (Triticum aestivumL.) and double‐crop soybean in a 2‐year rotation. On average, wheat yield was greater following corn or soybean than following grain sorghum. Yield of double‐crop soybean averaged 20% greater when wheat followed corn or grain sorghum than when wheat followed full‐season soybean. Tillage system influenced grain yield of double‐crop soybean more than it influenced wheat yield. Double‐crop soybean yield often was greater for continuous no‐till than for conventional or one‐time no‐till per cropping cycle. Soil analyses at the end of the study showed that total C and total N were greater for no‐till than for conventional in the 0‐ to 3‐inch depth, but total C and total N were greater for conventional than no‐till in the 3‐ to 6‐inch depth. In the multi‐cropping systems of the eastern Great Plains, both crop rotation and tillage system can significantly influence grain yield and selected soil properties.