Soybean Tillage and Planting Method Effects on Yield of Double‐Cropped Wheat and Soybeans1

Abstract Wheat (Triticum aestivum L., em Thell) following soybeans (Glycine max L., Merr) is an important cropping system throughout the southeastern United States. In this system, notillage soybean production is becoming a common practice; however, the effects of no‐tillage soybean production on yield of double‐cropped wheat are not well documented. The objective of this study was to determine the effects of three tillage practices and planting methods for soybeans on yields of soybean and wheat grown on Appling (Typic Hapludult) and Cedarbluff (Fragiaquic Paleudult) soils. Three primary tillage systems for soybeans were no‐tillage, cbisel, and moldboard plow and the three planting methods were drilled (18 cm rows), in‐row subsoiling (69 cm rows), and conventional (without subsoiling, 61 cm rows). The entire experimental area was disked (8 cm deep) prior to drilling wheat. In the three environments tested, no‐tillage soybean production without in‐row subsoiling reduced wheat grain yield an average of 509 kg/ha when compared to chiseling and moldboard plowing. Generally, planting soybeans with an in‐row subsoiler eliminated adverse effects of no‐tillage soybean production on wheat yield. No‐tillage soybean yields were not affected by planting methods except in 1 year where subsoiling increased yield 907 kg/ha (160%) over that obtained without subsoiling. Soybean yields were approximately equal for the chisel and plow treatments but wheat yields were often lower on the chiseled than on the plowed soil. The results suggest that plowing or at least chiseling prior to planting soybeans will result in higher yield of double‐cropped wheat than no‐tillage planted soybeans unless the soybeans are planted with an in‐row subsoiler.