** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** AN ECOLOGICAL NUTRIENT MANAGEMENT APPROACH INVOLVES PRACTICES THAT INCREASE AGROECOSYSTEM DIVERSITY, BUILD SOIL ORGANIC CARBON, AND REDUCE NITROGEN LOSSES THAT CAUSE GREENHOUSE GAS EMISSIONS AND WATER POLLUTION. AT REGIONAL SCALES, THE DEVELOPMENT OF CIRCULAR ECONOMIES CAN RECYCLE NUTRIENTS FROM LIVESTOCK MANURE AND HUMAN WASTE INTO VALUABLE FERTILIZERS. INTEGRATING CIRCULAR NUTRIENT ECONOMIES WITH ECOLOGICAL PRACTICES ON FARMS COULD OPTIMIZE SUSTAINABLE NUTRIENT MANAGEMENT, BUT THEIR COMBINED EFFECTS ON ECOSYSTEM SERVICES ARE UNKNOWN. OUR INTERDISCIPLINARY PROJECT WILL ADVANCE FOUNDATIONAL UNDERSTANDING OF TWO NOVEL SYSTEMS THAT COUPLE CIRCULAR ECONOMIES AND ECOLOGICAL NUTRIENT MANAGEMENT THROUGH THREE OBJECTIVES: (1) DETERMINE HOW ADAPTIVE MULTI-PADDOCK GRAZING OF COVER CROPS AFFECTS SOIL NITROGEN SUPPLY, MICROBIAL COMMUNITIES, AND SOIL CARBON FRACTIONS THAT REFLECT POTENTIAL SOIL CARBON STORAGE; (2) IDENTIFY HOW URINE-DERIVED FERTILIZER (UDF) IMPACTS SOIL NITROGEN CYCLING AND RETENTION, SOIL BIODIVERSITY, AND POTENTIAL FOR SOIL CARBON ACCRUAL WITHIN THE KELLOGG BIOLOGICAL STATION LONG-TERM AGROECOSYSTEM RESEARCH (KBS LTAR) EXPERIMENT; AND (3) EXAMINE BARRIERS TO, AND ENABLERS OF, WIDESPREAD ADOPTION OF COVER CROP GRAZING AND UDF AMONG FARMERS AND OTHER STAKEHOLDERS.OBJECTIVES 1 AND 2 WILL BE ADDRESSED THROUGH TWO FIELD EXPERIMENTS AT KBS IN SOUTHWESTERN MI: ONE AT THE KELLOGG FARM AND ONE IN THE LTAR CROPLANDS COMMON EXPERIMENT. WE WILL USE THE INTEGRATED CROP-LIVESTOCK SYSTEM AT KBS, AND PARTNER WITH A RANCHER AND TWO NEIGHBORING ROW CROP FARMERS IN CENTRAL MI, TO IDENTIFY TRADEOFFS AND SYNERGIES IN ECOSYSTEM SERVICES RELEVANT TO SOIL CARBON AND NITROGEN CYCLING WITH COVER CROP GRAZING IN DIFFERENT SOIL AND MANAGEMENT CONDITIONS. WE WILL LEVERAGE THE LTAR SITE AT KBS TO ESTABLISH SUBPLOTS WITHIN THE CROPLANDS COMMON EXPERIMENT THAT TEST OUTCOMES OF A VISIONARY MANAGEMENT SYSTEM INTEGRATING NUTRIENT RECOVERY FROM WASTE (UDF) WITH ECOLOGICAL PRACTICES. THE UDF EXPERIMENT WILL GENERATE NEW KNOWLEDGE OF AGROECOSYSTEM CARBON AND NITROGEN CYCLING WITH DIFFERENT NITROGEN SOURCES AND LEVELS OF CROP ROTATION DIVERSITY. OBJECTIVE 3 WILL BE MET THROUGH INTERVIEWS AND FOCUS GROUPS WITH FARMERS AND DIVERSE GROUPS OF KEY INFORMANTS IN MI, BUILDING ON RESEARCH AND LESSONS LEARNED FROM THE RICH EARTH INSTITUTE IN VERMONT AND FARMERS AND OTHER AGRICULTURAL PROFESSIONALS IN MICHIGAN. THE SOCIAL SCIENCE ANALYSIS WILL PRODUCE CRITICAL KNOWLEDGE ABOUT SOCIAL PROCESSES THAT ENABLE OR CONSTRAIN NOVEL ECOLOGICAL NUTRIENT MANAGEMENT SYSTEMS. WE WILL APPLY A CO-LEARNING APPROACH TO SHARE SCIENCE-BASED KNOWLEDGE THROUGH A FIELD DAY, ROUNDTABLE MEETING, AND OTHER OUTREACH ACTIVITIES.