|Frederick, James - CLEMSON UNIV.|
Submitted to: Southern Conservation Tillage for Sustainable Agriculture Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 5, 1999
Publication Date: N/A
Technical Abstract: When a double crop management system with drilled soybean and wheat led to high yields in deep-tilled small plots, we decided to evaluate the management system in large plots in a field with variable soil types. Double-cropped soybean and wheat were drilled in 7.5-inch row widths using all combinations of surface tillage (disked or none) and deep tillage (paratilled or none) with one extra set of paratilled treatments that were rotated with corn using in-row subsoiling. Cone indices were measured at two places in each plot to assess soil strength differences within and among treatments. Cone indices were higher for soil types with shallower B horizons. Subsoiled treatments had higher cone indices than paratilled treatments, partially as a result of drier soil. Disked treatments had equal or higher mean profile cone indices, even if they were deep tilled. In fact, at the position of maximum disruption by deep tillage, treatments had higher cone indices if they were disked than if they were not disked. A reduction in the loosening effect of the final deep tillage can be affected by earlier surface tillage.