Abstract
Agricultural management practices directly influence soil biological and chemical properties that impact the productivity and function of agroecosystems. Two components of soil that are extremely important to agricultural soil quality are soil carbon (C) and nitrogen (N). Benefits of soil C include soil structure, moisture, increased crop yield, and overall agricultural productivity. Soil N is often a limiting factor for plant growth and microbial communities, which are responsible for soil biogeochemical processes including organic matter stabilization. The implementation of no-till and or cover crops have been proposed as management practices to promote soil C and N stores, and microbial biodiversity in agroecosystems. However, little is known about the interactive effects of these different practices or how increased diversity over short time scales (e.g. planting diverse cover crops) impacts microbial communities and their function. This project aims to further increase knowledge on how management practices influence agroecosystem function by 1) evaluating the interactive effects of tillage and cover crops on soil C and N, 2) investigating how cover crop identity and diversity impact soil microbial community composition, and 3) determine how increasing levels of cover crop diversity affect C and N cycling by utilizing a stable isotope pulse-chase experiment. Conservation tillage and cover crops have successfully been used to improve soil quality and protect or improve soil organic matter and biodiversity. However, major barriers still exist when it comes to implementing these practices, partially due to lack of research evaluating the mechanisms underlying the effects of management practices across different ecosystems. Outcomes of this research will provide greater understanding of the mechanisms occurring belowground that drive biogeochemical cycles and agroecosystem function and stability.