Long-term cropping management practices affect the biochemical properties of an Alabama Ultisol

Authors: Watts, Dexter; He, Zhongqi; YIN, XINHUA - University Of Tennessee; Torbert, Henry - Allen; SENWO, ZACHARY - Alabama A & M University; Tewolde, Haile

Submitted to: Soil Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2024
Publication Date: 4/5/2024
Citation: Watts, D.B., He, Z., Yin, X., Torbert III, H.A., Senwo, Z., Tewolde, H. 2024. Long-term cropping management practices affect the biochemical properties of an Alabama Ultisol. Soil Systems. 8(2):41. https://doi.org/10.3390/soilsystems8020041.
DOI: https://doi.org/10.3390/soilsystems8020041

Interpretive Summary: Interest in improving the long-term sustainability of agricultural production systems has focused on identifying management practices that promote soil health. No tillage, cover cropping, and amending soils with poultry litter are commonly adopted conversation agricultural practices that have been shown to improve availability of soil nutrients and crop yield. However, the overall influence of these conservation agricultural practices on soil health in the southeastern US are not well understood. Measurements of soil biochemical properties can be used as indicators of the overall health of a soil because soil microbes and enzymes are responsible for cycling nutrients in soil. Thus, a study was conducted to evaluate the long-term influence of tillage, poultry litter applications, and cropping systems on soil biochemical properties. Adopting no tillage and adding poultry litter to the agricultural management systems changed the biochemical properties of the soil. Increases in the soil microbial biomass (sum total of all microorganisms) and soil enzymes associated with C and N cycling in soil increased with no tillage and poultry litter additions. Most of these changes occurred in the top few inches of soil. Results from this study suggest that long-term management of no tillage and poultry litter additions can potentially improve the health of degraded southeastern US soils.

Technical Abstract: Interest in improving the long-term sustainability of agricultural production systems has focused on identifying management practices that promote soil health. No tillage, cover cropping, and amending soils with poultry litter are commonly adopted conservation practices that have been shown to improve soil fertility and crop yield. However, the overall influence of these conservation practices on soil health in the southeastern US are not well understood. Measurements of soil biochemical properties can be used as indicators of the overall health of a soil. Thus, a study was conducted to evaluate the influence of tillage, poultry litter applications, and cropping systems on soil biochemical properties. Soils were collected in 2016 at the 0-5 and 5-10 cm depths from research plots that had been under long-term management (> than 25 years of tillage and 15 years of poultry litter application) and evaluated for soil microbial biomass and soil enzyme activities related to nitrogen cycling, soil protein and amino acid, and dissolved organic matter. Adopting tillage and poultry litter into the agricultural management system modified soil biochemical parameters of the soils evaluated. Most of the modifications occurred at the 0-5 cm depth. Higher microbial biomass C and N and enzyme activities of asparaginase and glutaminase were observed in the 0-5 cm under NT compared to those of conventional tillage (CT), indicating that greater biological activities have been established in these soil ecosystems. Poultry litter applications increased microbial biomass N and activities of asparaginase and glutaminase in both soil depths. In addition, microbial biomass P was increased following poultry litter application in the surface 0-5 cm depth. Results from this study suggest that long-term management of no tillage and poultry litter additions can potentially improve the health of eroded southeastern US soils by altering the soil biochemical parameters.