Benefits of Uniform Row Spacing in a Cotton-Corn Conservation System

Recommendations to obtain maximum yields of cotton and corn often don't occur with the same row spacing as it can vary based on the different crop's needs. However, many producers in the South are now rotating these two crops and are faced with the dilemma of either choosing unequal row spacing for each crop or growing both crops using uniform row spacing. An experiment was conducted at the E.V. Smith Research Center in South-Central Alabama on a Coastal Plain soil to determine the effect of uniform row spacing for a cotton-corn production system. Row spacing in this region is typically 36 in. for cotton and 30 in. for corn. Our treatments consisted of using this row spacing for each crop or using a standard row spacing of 36 in. for both crops. Because in-row subsoiling is also commonly practiced in this region, we also included this tillage practice in our production system. In-row subsoiling was conducted at three different times: (1) before corn planting, (2) before cotton planting, or (3) before both corn and cotton planting. A fourth control treatment with no in-row subsoiling was also conducted. Results after two years of the study indicate that, contrary to popular belief, maximum yields of corn were obtained with the uniform row spacing of 36 in. instead of the narrower row spacing of 30 in. It was also noted that when similar row spacing was used, in-row subsoiling conducted prior to the cotton crop provided maximum cotton yields with no decrease in corn yield in the following year. Controlled traffic combined with uniform row spacing was found to provide maximum yields of both crops as well as decreased energy use from the savings associated with the reduced need for annual in-row subsoiling.