EFFECTS OF TILLAGE AND CROPPING SEQUENCE ON SOIL PHYSICAL-PROPERTIES

The interactive effects of cropping sequence and tillage on soil physical properties are poorly documented. This type of information is essential if maximum efficiency is to be obtained from various farming systems. Field evaluations were conducted on a Ships clay (Udic Chromustert) - Weswood silt loam (Fluventic Ustochrept) intergrade in Burleson County, TX to determine the effects of three cropping sequences (continuous soybean (Glycine max (L.) Merr.), wheat (Triticum aestivum L.) - soybean doublecrop, and sorghum (Sorghum bicolor (L.) Moench)-wheat-soybean rotation) and two tillage methods (conventional disk tillage and no tillage) on soil bulk density, soil strength, and microaggregation. Tillage did not significantly influence soil bulk density or soil strength after 3 years. Conventional tillage significantly decreased microaggregation compared with no tillage at 0-76 mm after 3 years and at 0-152 mm after 6 years. Differences, however, were less dramatic in the sorghum-wheat-soybean cropping sequence as compared with the other sequences studied. Significant interactive effects were observed for cropping sequence × depth on soil bulk density, cropping sequence × tillage and cropping sequence × location (furrow vs. bed) on soil strength, and cropping sequence × tillage on microaggregation. © 1990.