Grain Yield and Yield Components of Doublecropped Winter Wheat as Affected by Wheat and Previous Soybean Production Practices

Development and grain yield of doublecropped winter wheat ( Triticum aestivum L.) are influenced by the production practices used to produce the wheat crop and potentially by those used to produce the previous crop. This 2‐yr field study was conducted on a Goldsboro loamy sand (fine‐loamy, siliceous, thermic Aquic Kandiudult) to determine whether production practices used in the spring to produce the previous soybean [ Glycine max (L.) Merr.] crop affect wheat grain yield and yield component responses to fall production practices. Treatments were deep tillage the previous spring prior to planting soybean using row widths of 19 or 76 cm, deep tillage in the fall prior to wheat planting, deep tillage in both the spring and fall, and no deep tillage for wheat planted with and without surface tillage. Fall deep tillage was the only treatment that consistently increased grain yield and all of the yield components; increasing grain yield, fertile head number per square meter, kernel number per head, and individual kernel weight by an average of 27, 11, 10, and 3%, respectively, over all other treatments. Grain yield and kernel number per square meter responses to fall deep tillage were greatest with no spring deep tillage, with no surface tillage, or when the previous soybean was grown using 76‐cm‐row widths. Grain yield, fertile head number per square meter, and kernel weight were all higher without surface tillage than with surface tillage. Results from this study show that production practices used to produce the previous soybean crop, such as row width and spring deep tillage, can have a significant effect on the grain yield and yield component responses of wheat to fall production practices.