Submitted to: Extension Reports
Publication Type: Experiment Station
Publication Acceptance Date: 1/1/2007
Publication Date: 3/30/2007
Citation: Mitchell, C.C., Delaney, D.P., Balkcom, K.S. 2007. More record cotton yields on the Old Rotation, 2006. In: Lawrence, K.S., Monks, C.D., Delaney, D.P., editors. 2006 Cotton Research Report, Alabama Agricultural Experiment Station, Research Report No. 30. p. 17.
Technical Abstract: The Old Rotation is the oldest, continuous cotton experiment in the world. It consists of 13 plots on 1 acre of land designed to document the long-term effects of crop rotations with and without winter legumes (crimson clover) as a source of nitrogen for cotton, corn, soybean, and wheat. In spite of severe dry weather throughout Alabama in 2006, crops continued the trend that began in 1996 when the experiment was changed from conventional tillage to conservation tillage. Another record cotton yield of 1760 lb lint ac-1 was produced on the non-irrigated half of the treatment following corn and crimson clover cover crop plus 120 lb N ac-1. After 4 years, no yield advantage has been demonstrated for irrigated cotton at this location. Explanations for this lack of advantage include 1) timely rainfall; 2) improved infiltration, soil water holding capacity, and depth of rooting attributed to long-term conservation tillage; and 3) poor irrigation timing. On the other hand, corn and soybean have responded favorably to irrigation.