Effect of rye cover crop management methods on cotton growth in a conservation system

Authors: Kornecki, Ted

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2018
Publication Date: 9/6/2018
Citation: Kornecki, T.S. 2018. Effect of rye cover crop management methods on cotton growth in a conservation system. Journal of Cotton Science. 22(2):104-116. https://doi.org/10.56454/MBIU6609.
DOI: https://doi.org/10.56454/MBIU6609

Interpretive Summary: A three-year field experiment was conducted at two Alabama locations evaluating effects of rye cover crop termination methods (rolling directions) and different row-cleaners on no-till cotton. Central and northern Alabama locations were selected to account for different climatic and soil conditions. Based on the results in this study the following rolling directions and row cleaners are recommended for optimum no-till cotton production. When rye produces large amounts of residue, the parallel rolling direction and commercial row cleaners such as DawnTM or YetterTM are recommended for optimum cotton growth. When rye is not rolled down, utilization of row cleaners is required, especially with custom designed spring loaded pushers that press residue against the soil surface so cotton can be planted into standing rye without interference between rye residue and planting equipment. Regardless of height and the amount of rye residue, perpendicular and diagonal rolling directions are not recommended even when row cleaners are used. Not using row cleaners in high residue systems also affects seed cotton emergence and yield, resulting in lower seed cotton yield as seen at a central Alabama location in 2006 and 2008. The parallel rolling direction minimized accumulation of residue on row cleaners and time required to clean residue from row cleaners.

Technical Abstract: Cover crops have been recognized as a vital part of conservation agriculture. However, cover crops must produce optimum biomass to be effective. Because of the large amount of residue produced by cover crops, they must be managed appropriately to avoid planting problems. Roller/crimpers have been used to manage cover crops by flattening them and creating a thick mat over the soil surface. A study was conducted to determine the effects of different rolling directions (parallel, diagonal, and perpendicular to the cotton planting direction) using a roller/crimper, and three row cleaners (DawnTM, YetterTM, and DawnTM with a custom residue pusher attachment, and no row cleaner) on cotton stand, emergence rate, and yield. Two locations were chosen for this study: E.V. Smith Research and Extension Center (EVS) in central Alabama and Tennessee Valley Research and Extension Center (TVS) in northern Alabama to account for different climatic and soil conditions. A split (strip) plot design with four replications was utilized in this study. Presented results cover three growing and harvest seasons from 2006 to 2008. Cereal rye was chosen as the cover crop due to its popularity with Alabama producers because of large biomass production. Rye was rolled at the early milk growth stage and terminated with a roller/crimper with supplemental application of Roundup (glyphosate). Data indicate that the parallel rolling direction and non-rolled residue treatments with the presence of any of the commercial and custom row cleaners produced the highest cotton stand and yield at both locations in all three years. In three growing seasons all row cleaners resulted in higher cotton stand at both locations when compared with no-row cleaners. The DawnTM row cleaner with custom made pusher also resulted in a greater cotton stand especially for non-rolled residue due to pushing of the rye residue against the soil surface while planting, thus reducing interference of residue with the planting units. During three growing seasons at both locations, the Emergence Rate Index (ERI) showed that the fastest emergence was observed with the parallel rolling direction and all tested row cleaners. The slowest emergence rate was observed with perpendicular and diagonal directions and no row cleaners. Parallel rolling direction minimized accumulated rye residue on row cleaners and the cleaning time from row cleaners. However, rye residue accumulation on the DawnTM row cleaner was higher and required more time to clean from the planter.