**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** NITROGEN (N) FERTILIZER IS ESSENTIAL FOR CONSISTENT AGRICULTURAL YIELDS, STILL, N LOSS FROM AGRICULTURAL SYSTEMS POSES ENVIRONMENTAL THREATS. SUSTAINABLE AGRICULTURAL MANAGEMENT AIMS TO REDUCE EXCESSIVE N IN THE SOIL BY LEVERAGING ECOSYSTEM SERVICES OF COVER CROPS. CROPS CAN USE ONE OF TWO STRATEGIES TO MANAGE N CONCENTRATIONS IN THE SOIL: 1) BIOLOGICAL NITROGEN FIXATION (BNF; NATURAL ACCUMULATION OF N) AND 2) BIOLOGICAL NITRIFICATION INHIBITION (BNI; N LOSS PREVENTION). THESE PROCESSES ARE CONTRADICTORY; ONE PLANT SPECIES CAN RARELY FACILITATE BOTH. THIS RESEARCH AIMS TO INVESTIGATE THE ABILITY OF MEADOWFOAM (LIMNANTHES ALBA), A SEED CROP, TO STIMULATE BNF AND BNI IN THE SOIL THROUGH INTERACTIONS WITH MICROBES. LABORATORY AND FIELD EXPERIMENTS, COMBINED WITH NOVEL TECHNIQUES THAT CAN IDENTIFY MICROBES AND TRACK N, WILL ALLOW FOR STUDYING MEADOWFOAM'S ROLE IN N CYCLING IN GRASS SEED CROPPING SYSTEMS IN THE WILLAMETTE VALLEY, OREGON. THE RESULTS OF THIS STUDY WILL ADVANCE RESEARCH INVESTED IN OPTIMIZING THE N CYCLE, WHICH HAS SIGNIFICANT ECONOMIC AND ENVIRONMENTAL BENEFITS FOR FARMERS. THIS RESEARCH MAY IDENTIFY A NEW MARKET OPPORTUNITY FOR MEADOWFOAM AS A COVER CROP, BENEFITING SEED PRODUCERS AND DISTRIBUTORS IN THE WILLAMETTE VALLEY. IF IMPLEMENTED AS A COVER CROP, MEADOWFOAM MAY INCREASE SOIL FERTILITY AND REDUCE N LOSSES IN OTHER REGIONS. THIS WORK ALIGNS WITH BROADER FARM BILL GOALS BY ADDRESSING THE PRIORITIES OF BIOENERGY, NATURAL RESOURCES, AND ENVIRONMENT WITHIN THE PROGRAM AREA SUSTAINABLE AGROECOSYSTEMS: HEALTH, FUNCTIONS, PROCESS AND MANAGEMENT.