My research examines cover crop roots and associated ecosystem services. Cover crop mixtures are increasingly being adopted to provide essential ecosystem services (e.g., soil health, nutrient, and weed management) and increase sustainability within agricultural landscapes. The lack of effective methods to characterize belowground plant species composition remains a major barrier to understanding the relationship between structure and function within cover crop mixtures. To address this issue, I modified the amplicon sequencing approach with extensive calibration to determine the abundance and composition of different species from the biomass of unknown mixtures. With the belowground community characterized, we can examine how cover crop species allocate their biomass between roots and shoots in mixture and monoculture treatments to 1) evaluate how closely the aboveground composition predicts the belowground composition in cover crop mixtures and make inferences based on yearly abiotic factors, 2) determine how species alter their root mass fraction (RMF) and depth proportions between treatments, and 3) assess how those differences relate to root-linked ecosystem service provisioning. Services of focus include active carbon, deep soil nitrogen retention, and biological nitrogen fixation. Ultimately, I hope to inform growers of mixture choice based on the specific services they desire cover crop mixtures to provide.