Cover Crop Use for Managing Broiler Litter Applied in the Fall

Abstract

Increasing interest of using broiler litter in the fall for row crops has implications for leaching losses of nutrients, particularly N. Any cultural practice that prevents nutrient losses could be agronomically beneficial and improve soil fertility. A field study was conducted in 2007 and 2008 on Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts) soil to evaluate the impacts of a winter rye (Secale cereal L.) cover crop and broiler litter timing on cotton (Gossypium hirsutum L.) yield, yield components and leaching loss of NO3–N. Broiler litter was applied to the soil at the rates of 0, 4.5, 9, and 13.4 Mg ha−1 in the fall and spring for both cover and no cover crop and incorporated immediately. Winter rye cover crop was planted following broiler litter application in the fall. Averaged across cropping system and broiler litter timing, cotton lint yield and yield components increased with increasing broiler litter application. Application of broiler litter at a rate >9 Mg ha−1 was not advantageous and exceeded N need for optimum lint yield as evidenced by increasing postharvest NO3–N in the soil profile. In the absence of cover crop and averaged across litter rates, spring‐applied broiler litter had the best agronomic response and increased lint yield by 19 and 18% compared with fall‐applied litter in 2007 and 2008, respectively. Seeding a winter rye cover crop to fall‐applied broiler litter did not benefit cotton lint yield and yield components but substantially reduced leaching loss of NO3–N.