SOIL HEALTH MANAGEMENT PRACTICES, SUCH AS COMPOST AMENDMENTS AND COVER CROPPING, HAVE GROWN IN POPULARITY DUE TO THEIR ABILITY TO IMPROVE SOIL PHYSICAL, CHEMICAL, AND BIOLOGICAL CHARACTERISTICS. HOWEVER, IMPACTS OF THESE PRACTICES ON PLANT PATHOGENS IN SOIL REMAIN UNCLEAR, DESPITE BEING CRITICAL TO UNDERSTANDING SOIL HEALTH OUTCOMES. TO ENABLE PRODUCERS TO BUILD HEALTHY SOILS WHILE MAINTAINING CROP YIELDS UNDER PATHOGEN PRESSURE, THE GOAL OF THIS INTEGRATED RESEARCH AND EXTENSION PROJECT IS TO ENHANCE DEVELOPMENT AND ADOPTION OF APPROACHES FOR CO-MANAGING SOIL HEALTH AND PLANT DISEASE. PROJECT OBJECTIVES WILL BE CENTERED ON A BROAD HOST RANGE FUNGAL PATHOGEN (SCLEROTIUM ROLFSII) AND DISEASE SYNDROME (FUSARIUM WILT) WITHIN THE CONTEXT OF CALIFORNIA PROCESSING TOMATOES, AN INDUSTRY REPRESENTING OVER 90% OF THE NATIONAL PROCESSING TOMATO MARKET. FOR OBJECTIVE 1 (RESEARCH), WE WILL INVESTIGATE HOW LONG-TERM INPUTS OF ORGANIC VERSUS SYNTHETIC SOIL FERTILIZERS AND CROPPING SYSTEMS THAT ENHANCE SOIL NITROGEN AFFECT PATHOGEN SURVIVAL ON CROP RESIDUE. FOR OBJECTIVE 2 (RESEARCH), WE WILL EXPLORE THE EFFECT OF COMPOST AND CRABMEAL AMENDMENTS ON PERSISTENCE OF PATHOGENS WITH DIFFERING MODES OF SURVIVAL IN SOIL AND ELUCIDATE BIOLOGICAL INDICATORS OF PATHOGEN-SUPPRESSIVE SOIL. FOR OBJECTIVE 3 (EXTENSION), WE WILL DESIGN AND IMPLEMENT A WORKSHOP ON CO-MANAGEMENT OF SOIL HEALTH AND PLANT DISEASE, AS WELL AS DISSEMINATE PROJECT FINDINGS AND ENCOURAGE ADOPTION OF SYSTEMS-BASED APPROACHES THROUGH INTEGRATION OF STAKEHOLDER FEEDBACK. THE EXPECTED GENERAL IMPACTS ARE IMPROVED SOIL HEALTH ACROSS CROPPING SYSTEMS, IMPROVED SOILBORNE PATHOGEN MANAGEMENT, INCREASED CROP YIELD AND QUALITY, FEWER APPLICATIONS OF ENVIRONMENTALLY-RISKY CHEMICAL PESTICIDES, GREATER PROFITS FOR FARMERS AND PROCESSORS, AND THE SOCIETAL BENEFIT OF IMPROVED CAPACITY FOR FOOD PRODUCTION. AS GUIDED BY CONSTRUCTIVE MENTORING AND SUBSTANTIVE EVALUATION PLANS THAT ARE RELEVANT TO ADVANCING SCIENCE IN ALIGNMENT WITH AFRI EWD GOALS, THIS FELLOWSHIP WILL ALSO ENRICH ACADEMIC COMPETENCY OF THE PROJECT DIRECTOR IN APPLIED PLANT PATHOLOGY AND OUTREACH, AS WELL AS EXPAND THE PROFESSIONAL SKILLSET OF THE PROJECT DIRECTOR TO INCLUDE SOIL MICROBIAL COMMUNITY ANALYSIS AND SOIL HEALTH MANAGEMENT, THEREBY SUPPORTING THEIR GOAL OF CAREER INDEPENDENCE IN COOPERATIVE EXTENSION.