Integrated effects of tillage, fertilizer sources and a rye cover crop on dryland cotton production

Implementing an integrated system of reduced tillage and cover cropping holds promising potential for enhancing cotton (Gossypium hirsutum L.) production in the southeast, where soils are eroded and low in organic matter. A 4-year field study was conducted on a Leeper silty clay loam at the Plant Science Center at Mississippi State University to investigate the combined effects of no-till (NT) and conventional tillage (CT), with applied broiler litter (BL) and inorganic N fertilizer, in the presence of winter cover crops (WCCs) and absence of cover crops on cotton growth and yield. With WCC residues, NT had the greatest soil moisture in the drier year of 2022. Total aboveground biomass of WCC and nitrogen (N) accumulation were 72% and 60% greater in the 2019/2020 growing season than in the 2020/2021 and 2021/2022, and they were 24% and 22% greater with CT than NT. However, cotton dry matter (DM) was 22% greater with NT than CT. With WCC residues, cotton DM, N uptake, and leaf area index were greater by 25%, 21%, and 64%, respectively. Regardless of tillage and cropping systems, BL in the presence of WCC residues increased cotton lint yield by 67%, especially in years with less rainfall during cotton peak blooming and boll formation. This study revealed that the integration of NT with BL and inorganic N fertilizer in the presence of a cover crop can have a positive effect on cotton production. Implementing these practices could enhance long-term sustainable cotton cultivation in southeastern United States agroecosystems.