Integrated effects of tillage and fertilizer sources with cover crop on dryland cotton

Authors: Adeli, Ardeshir; Brooks, John; Miles, Dana; Read, Quentin; Huang, Yanbo; Feng, Guanglong; Jenkins, Johnie

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2025
Publication Date: 3/1/2025
Citation: Adeli, A., Brooks, J.P., Miles, D.M., Read, Q.D., Huang, Y., Feng, G.G., Jenkins, J.N. 2025. Integrated effects of tillage and fertilizer sources with cover crop on dryland cotton. Agronomy Journal. 2025(117):e70019. https://doi.org/10.1002/agj2.70019.
DOI: https://doi.org/10.1002/agj2.70019

Interpretive Summary: Cotton (Gossypium hirsutum L.) has long been one of the primary agronomic crops in the southeastern United States. As global demand for cotton continues to rise, sustainable agricultural practices that optimize cotton growth and yield are becoming increasingly crucial. Soil tillage and nutrient management play pivotal roles in establishing sustainable agricultural practices. While conventional tillage operations can render soil susceptible to erosion and accelerate the depletion of soil organic matter, cotton production under conventional tillage remains common in many southeastern U.S. regions. Additionally, the implementation of conservation tillage systems, such as No-Till, is becoming a common cultural practice in the southeastern United States and approximately 60% of cotton production in Mississippi utilizes No-Till methods. Since accumulation of plant residues on the soil surface can act as a protective barrier, mono culture dry land cotton under No-Till system results in less plant residue compared to other row crops like corn. Application of plant nutrients such as fertilizer or manure to the fields under No-Till systems, undergoes rapid decomposition and loss of essential nutrients through volatilization and runoff. Cover crops are a novel concept and leave a significant amount of biomass (residue) on the soil surface which protect nutrient from loss. We hypothesized that the long-term combination of tillage systems, cover crops, and organic fertilizers such as BL can enhance soil N availability, reduce N leaching loss, and sustain cotton production.The objective of our study was to investigate the integration of NT and CT, along with fall-applied BL, in the presence and absence of winter cover crops on dryland cotton growth and yield within the southeastern agroecosystem.

Technical Abstract: Implementing an integrated system of reduced tillage and cover cropping holds promising potential for enhancing cotton (Gossypium hirsutum L.) production, particularly in the southeast where soils are partially eroded and low in organic matter. A four-year field study was conducted on Leeper silty clay loam soil at the Mississippi State Plant Science Center to investigate the combined effects of No-Till (NT) and Conventional Tillage (CT), along with fall-applied broiler litter (BL), in the presence and absence of winter rye cover crop (WCC) residues on soil moisture, soil available nitrogen (N), and dryland cotton growth and yield. In the presence of WCC residues, No-till system had the highest soil moisture at the top 15 cm depth from flowering through boll formation in drier year of 2022. Total aboveground biomass of WCC and N accumulation were 72% and 60% greater in the 2019/20 growing season than in the 2020/21 and 2021/22 due to more cumulative rainfall and warmer temperatures and they were greater with CT than NT system. However, cotton dry matter and N uptake were found higher with NT than CT system. In the presence of WCC residues, cotton DM, N uptake, and leaf area index (LAI) were significantly greater by 25%, 21%, and 64%, respectively. Using No-Till methods along with BL in the presence of WCC residues considerably increased cotton lint yield, especially in years with less rainfall, during the critical growth stages of cotton. Additionally, the amount of nitrate-N in the soil with BL was 24% higher compared to using inorganic N fertilizers before planting cotton. Implementing these practices could enhance the long-term sustainable cotton cultivation under southeast agroecosystem.