Influence of Tillage and Crop Rotation on Yields of Corn, Soybean, and Wheat

Abstract Cropping systems for minimum or no tillage have been developed to produce corn (Zea mays L.) yields equal to or higher than yields obtained in conventional tillage systems, but limited research has been conducted with tillage systems involving corn and soybean [Glycine mar (L.) Merr.] rotations. The objective of this study was to compare different cropping sequences of corn, soybean, and wheat (Triticum aestivum L.) in conventional, strip, and no tillage. A field experiment was conducted on a Hartsell fine sandy loam (fine‐loamy, siliceous, thermic Typic Hapludults). In 1981, corn yields with no tillage were 30% lower than those from conventional tillage systems. No corn yield differences were observed in 1982 and 1984 due to tillage or crop rotation; however, in 1983, strip and no tillage in conjunction with soybean in the rotation increased corn grain yields by 12%. Soybean yields in strip and no tillage decreased 16% compared to conventional tillage yields in 1981, but in subsequent years, soybean yields increased with those systems. A significant tillage × rotation interaction in 1981, 1982, and 1983 was caused primarily by a buildup of soybean cyst nematode (Heterodera glycines Ichinohe) (SCN) population with conventional tillage and continuous soybean. Rainfall affected soybean yields more with conventional tillage than with strip or no tillage. The conservation tillage systems (strip or no‐tillage system) in combination with corn‐soybean rotation for both full‐season or double‐cropped soybean gave the most consistent yield increase for the 4 yr.