Building belowground diversity with cover crops to enhance agroecosystem resilience to climate change

NON-TECHNICAL SUMMARY: Meeting the food, fiber, and energy needs of a growing global population in the face of climate change is the most significant challenge of the 21st century. Nitrogen (N) is at the heart of this challenge. Agriculture must supply adequate N to crops to meet yield goals but also reduce N losses to the environment. These goals require stronger focus on retaining N, an ecosystem service driven by soil microbes. This project will assess the potential of multi-species cover crop mixtures to strengthen N cycling by cultivating belowground diversity. I propose that cover crop mixtures will cultivate soil microbial communities of greater diversity and stability. This combination of above- and below-ground diversity will lead to greater resilience of N cycling in response to climate variation. To test these hypotheses, I will monitor microbial diversity, soil respiration, and inorganic N within a long-term study of cover crop mixtures embedded in a three year crop rotation. I will use complimentary approaches to characterize microbial diversity in response to cover crops and climate variation: community level physiological profiling, phospholipid fatty acid analysis, and molecular analysis. This research responds to growing farmer interest in cover crop mixtures and will explore the impacts and ecosystem services derived belowground in connection with this promising strategy. Through hands-on field days and web-based training, the results of this research will assist farmers in making informed agronomic decisions that advance the practice of sustainable agriculture.