RHIZOBIAL CYCLING BETWEEN DIVERSE LEGUMES IN CROP ROTATIONS: UNDERSTANDING THE EFFECTS ON SOIL AND PLANT HEALTH

The goalofthis proposal is to explorethe possibility of leveraging legume cover crops to enrich soil microbiomes for specific rhizobia communities that benefit cash crops and increase soil health.In particular, this proposal will test the hypothesis that rhizobial cycling and effective N-fixation depends on the specificity and degree of symbiotic partner overlap between cover crop and focal crops.Aim 1 and 2 will leverage an existing cover crop mixtures field experiment to measure rhizobia sharing between legume cover crops and focal cash crops. The greenhouse experiment in Aim 3 will test a broader panel of cover cropand cash crop species.Aim 1:Measure nodule and rhizosphere microbiomes of legume cover crops grown singly and in mixtures across multiple years in a long-term field experimentNodule and rhizosphere sampling (Fall and Spring 2021-2024)Extract & Seq. Samples (Yearly)Analysis & Writing (2024)Aim 2: Test for legacies of cover crops on soybean nodule and rhizosphere microbiomesNodule and rhizosphere sampling (Early Fall 1/1/202223)Conduct Competition Experiment (Winter 2023)Analysis & Writing (2024)Aim 3: Measure the effect of cover crop microbiomes on legume cash crop and soil healthFinalize plant species identities (Early 2022)Conduct Greenhouse Experiment (2023)Analysis & Writing (2024)