|SHANKLE, MARK - Mississippi State University|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2019
Publication Date: 5/23/2019
Citation: Adeli, A., Brooks, J.P., Read, J.J., Shankle, M.W., Feng, G.G., Jenkins, J.N. 2019. Poultry litter and cover crop integration into no-till cotton on upland soil. Agronomy Journal. 111:2097-2107. https://doi.org/10.2134/agronj2018.05.0328.
Interpretive Summary: Implementation of conservation tillage systems, such as no-till and including poultry litter applications to cotton, may increase nutrient concentrations in the soil surface and increase potential losses of nutrients via runoff and ammonia volatilization. Understanding the dynamics of derived-nutrients from poultry litter into the soils under a no-till system play an important role in management practices for any farmer or regulator to avoid undesirable environmental impact. In a no-till system field, plant residue has been shown to have major contribution in reduction of plant nutrient losses. Monoculture cotton leaves less quantity of plant residue on the soil surface as compared to other row crops such as corn. Several researchers reported that cover crops have been promoted as a means of maximizing the efficient use of available N to subsequent crops in agricultural systems, potentially enhancing profitability through reduce nutrient leaching losses, reduce inorganic fertilizer N requirement, improve soil and water quality, improve soil moisture and microbial enrichment. The scavenging ability of cover crops to sequester and reducing N leaching loss has also been documented by several workers. Integration of cover crop and animal by-products into row crops under conservation tillage may benefit crop growth and yield. The asserted influence from long-term poultry litter and cover crops under no-till cropping system in upland soils on soil C and subsequent soil health is largely unknown. The objective of this study was to evaluate the effects of cover crop (winter rye vs. winter fallow) along with broiler litter fertilization on cotton growth, yield, soil microbiology and soil health.
Technical Abstract: A field study was conducted in an upland soil for four years to determine the effects of winter wheat (Triticum aestivum L.) cover crop and poultry litter on no-till cotton (Gossypium hirsutum L.) yield grown in narrow (0.75 m) and conventional (1.01 m) row spacing. The experimental design was randomized complete block with a 2 × 2 × 3 treatment arrangement with three replications. Fertilization treatments include an unfertilized control, state recommended inorganic fertilizers and poultry litter. The results showed that cotton lint yield was significantly greater with poultry litter than inorganic fertilizer application in each year. Cover crop significantly increased lint yield as compared to no cover in drier seasons but not in wet seasons. However, in residual plots in which poultry litter was terminated, cotton lint yield was increased by 12% in the absence of cover crop residue. Application of poultry litter in the presence of cover crop residue enhanced soil C by 22% mainly at the top 15 cm soil depth. Poultry litter also increased soil Gram-negative bacteria, 16S rRNA, and ureC levels in soils collected following 3 years of application, while cover crop doubled heterotrophic plate count bacteria. Application of poultry litter on the top of cover crop residue reduced soil penetration resistance and bulk density by 9 and 3.5%, respectively and increased water aggregate stability by 7.4% as compared to unfertilized control. Integration of poultry litter and cover crop residue into no-till cotton increased cotton growth, and yield and improved soil health including soil microbiology.