Effects of cover crop termination and cotton planting methods on cotton production in conservation systems

Abstract

AbstractIn conservation agriculture, cover crops are utilized to improve soil properties and to enhance cash crop growth. One important part of cover crop management is termination. With smaller profit margins and constraints on time and labor, producers are searching for ways to reduce time and labor required to terminate cover crops while maintaining or increasing profitability. This study examined the effect of 11 different combinations of terminating cereal rye (Secale cerealeL.) and planting cotton (Gossypium hirsutumL.) on population, seed cotton yield, total costs and net returns; and how combined operations affect labor, fuel consumption and carbon (CO2) emissions in a conservation system. Cereal rye followed by cotton was planted in central Alabama during the 2009–2011 crop years. Treatments included cotton planted directly into standing cereal rye, cover crops terminated at early milk growth stage using mechanical (roller or roller/crimper) with or without chemical termination (spraying) followed by cotton planting, and cover crop termination combined with cotton planting using spraying with or without rolling termination. While the 2011 crop year had the lowest plant populations, there was no year effect on seed cotton yields, total costs or net returns. Rolling with or without spraying yielded higher plant populations (26%), seed cotton yields (18.3%) and net returns (17.2%) than cotton planted into standing rye; however, rolling with or without spraying also had 23.8% higher costs due to increased fuel usage, machinery and labor hours, and yield varying costs. While rolling with spraying had slightly higher total costs compared with rolling alone (6.5%), plant populations, seed cotton yields and net returns were 11.42%, 6.4% and 6.5% higher, respectively. Converting from three separate operations for cover crop termination and cotton planting to rolling and spraying combined with planting, producers could potentially reduce CO2emissions from fuel use and labor hours associated with cover crop termination and cotton planting by up to 51%.