Tillage Management Influence on Microbial Activity and Carbon Cycling Dynamics in Brazos Riverbottom Soil

Abstract

Conventional tillage (CT) practices can affect the chemical, physical, and biological health of soil, which alter microbial access to carbon (C) and nutrients from crop residues. Few studies investigate how tillage effects the biological function of soil. This study identifies the effects of CT versus no-till (NT) management in a long-term agricultural system (38 years) by measuring 5 C and nutrient cycling microbial enzymes, as well as C pools. Under NT, soil organic and active C was greater than under CT. Tillage had no significant effect on most extracellular enzyme activities (EEAs). However, there were differences in EEAs across the growing season, where activities were lowest during harvest and highest in early midseason at 0-5 cm depth. Increased C in NT may be due to delayed decomposition due to residue retention. Seasonal effects in enzyme activity may be due to plant-soil interactions associated with nutrient requirements of plants. Switching to NT management can improve the health and function of the soil and increase agricultural C storage.