Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/8/2009
Publication Date: 1/8/2009
Citation: Raper, R.L., Balkcom, K.S., Arriaga, F.J., Price, A.J., Kornecki, T.S., Schwab, E.B. 2009. Benefits of uniform row spacing in a cotton-corn conservation system. In: Boyd, S., et al., editors. Proceedings of the 2009 Beltwide Cotton Conference, January 5-8, 2009, San Antonio, Texas. p. 1514-1519. Interpretive Summary: As producers embrace crop rotations to improve their soil quality and overall productivity, additional guidance is needed on the most appropriate row spacings for different crops. Crops respond differently to spacing and improved yields can often be obtained with different row widths. However, reduced tillage systems may offer opportunities for common row spacings. Preliminary results from the research study showed that improved corn yields were found with common row spacing of the corn and cotton rotation. Improved soil condition resulting from controlled traffic was mostly responsible for improved crop yields. Completion of this research project will determine if cotton yields are likewise affected.
Technical Abstract: Recommendations to obtain maximum yields of cotton (Gossypium hirsutum L.) and corn (Zea mays L.) often don't occur with the same row spacing due to different crop's needs and available equipment. 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 rotation system. Row spacing in this region is typically 36 in. for cotton and 30 in. for corn. Our treatments consisted of using these row spacings 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) biennially before corn planting, (2) biennially before cotton planting, or (3) annually before both corn and cotton planting. A fourth control treatment with no in-row subsoiling was also evaluated. 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 the following year. Controlled traffic combined with uniform row spacing of 36 in. produced maximum yields of both crops as well as decreased energy use associated with reduced annual in-row subsoiling.