|Motta, A C - UNIV FED DO PARANA BRAZIL|
|Burmester, C - AUBURN UNIVERSITY|
Submitted to: Meeting Abstract
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 10, 2003
Publication Date: August 11, 2003
Citation: Motta, A.V., Reeves, D.W., Burmester, C.H., Raper, R.L. 2003. Effects of tillage systems, rotations and cover crop on soil strength. Proceedigs of the II World Cogress on Conservation Agriculture-Producing in Harmony with Nature. p. 494-497. Technical Abstract: Continuous cotton (Gossypium hirsutum L.)production in the southern USA with intensive tillage has resulted in decreased soil quality. Conservation tillage can reverse this trend, but no-tillage often results in soil compaction problems. In May 2001, we determined soil strength from a long-term (22 years) replicated cotton rotation experiment on a Decatur silt loam (fine, kaolinitic, thermic, Rhodic Paleudults) in the Tennessee Valley of northern Alabama. We used a recording penetrometer to measure soil strength in-row and in non-trafficked and trafficked middles, to a depth of 60-cm in seven management systems. Systems included: continuous cotton with conventional tillage or no-tillage, with and without a wheat (Triticum aestivum L.) cover crop; cotton rotated with soybean [Glycine max (L.) Merr.]or corn (Zea mays L.); and cotton rotated with doublecropped soybean/wheat. No-tillage without cover cropping resulted in highest soil strengths and shallower depths for maximum soil strength. Inclusion of a wheat cover crop increased depth of maximum soil strength from 10-cm to 21-cm in no-tillage in the in-row position, and tended to reduce maximum soil strength values. Cotton rotated with doublecropped soybean/wheat also resulted in a deeper depth for maximum soil strength but did not reduce maximum soil strength values. Historically, wheat as a grain rotation or cover crop often produced the greatest yield benefits to the following cotton crop. The data suggest that a cereal crop in rotation as a grain crop or cover crop is critical for no-tillage cotton, and that one benefit of the cereal grain/cover crop is amelioration of soil compaction.