The Effects of Combined Cover Crop Termination and Planting in a Cotton No-Till System

Abstract

Abstract. One method to save resources while positively impacting the environment is combining agricultural field operations. In no-till systems, cover crop termination and cash crop planting can be performed simultaneously utilizing a tractor as a single power source. A no-till field experiment merging cover crop management with cotton planting was conducted in 2012, 2013, and 2014 in central Alabama to study the effects on saving operation time, fuel consumption (reduced emissions), and the effects on cotton population and yield. This field test included two cotton planting dates where planting operations and cover crop termination (using rollers/crimpers with and without herbicide) were combined into one operation or conducted separately. These combined or separate operations occurred 10 and 20 days after rye reached the early milk growth stage. One treatment was planting cotton into standing rye (no rolling or glyphosate). For the standard practice, the cereal rye cover crop was terminated (rolling and glyphosate) at the early milk growth stage, and cotton was planted 20 days later. Thus, the six treatments included combined operations with or without glyphosate (rolling rye using a roller/crimper and planting using a no-till planter), separate operations with and without glyphosate using the same equipment, planting into standing rye, and the standard practice. All treatment operations were conducted at an operating speed of 4.8 km h -1 . Averaged over three growing seasons and treatments cotton population was higher for 20 days after early milk rye growth stage (91727 plants ha -1 ) compared to 10 days after this stage (74863 plants ha -1 ). In three years, cotton population was influenced by treatments 10 days after this selected growth stage, but not after 20 days. Overall, cotton planting date did not affect seed cotton yield (3036 kg ha -1 ) for 10 days after the selected growth stage, compared to 3127 kg ha -1 for 20 days after this stage. However, there were significant treatment differences in seed cotton yield for 10 days after the selected growth stage. In contrast, for 20 days after the selected stage, rolling/planting treatments did not affect seed cotton yield. Since there were no significant differences in seed cotton yield for 20 days after the rye early milk growth stage, combining rye termination and planting cotton operations might be a valuable option for saving fuel, reducing engine emissions to the environment, and saving cover crop management and cotton planting time. Fuel consumption was 7.5 L h -1 and 9.3 L h -1 for separate rye rolling and cotton planting operations, respectively (overall fuel usage of 16.8 L h -1 ). In contrast, the fuel usage from combined rolling and cotton planting was only 9.7 L h -1 . Compared to separate rye rolling and cotton planting operations, this lowered fuel consumption by 7.1 L h -1 (42% reduction). In addition, combined operations take half the time and reduce labor cost compared to conducting them separately at the same operating speed.