** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** A KEY COMPONENT OF MANAGING CROPS TO WITHSTAND ENVIRONMENTAL STRESS IS OPTIMIZING BENEFICIAL PLANT-MICROBE INTERACTIONS THAT IMPROVE WATER AND NUTRIENT AVAILABILITY TO PLANTS AND DETER PATHOGENS. STRATEGIES TO ACHIEVE THIS INCLUDE USE OF COVER CROPS TO STABILIZE SOIL AND SUSTAIN DIVERSE SOIL MICROBIAL COMMUNITIES, AND ADDITION OF COMPOST TO SUPPLEMENT CARBON AND NUTRIENTS AND IMPROVE SOIL PROPERTIES. BENEFITS FROM THESE STRATEGIES ARE SLOW TO EMERGE IN HOT, SEMI-ARID ENVIRONMENTS SUCH AS THE TEXAS SOUTHERN HIGH PLAINS (SHP), THE LEADING COTTON PRODUCTION AREA IN THE U.S. WHERE CROP AND BIOLOGICAL ACTIVITIES ARE LIMITED BY WATER AND NUTRIENT AVAILABILITY, DISCOURAGING GROWERS FROM INVESTING IN THESE PRACTICES. WE ALSO KNOW LITTLE ABOUT SOIL MICROBIOMES AND HOW THEY ARE INVOLVED IN CROP RESPONSE TO DROUGHT AND PATHOGENS IN THESE ALREADY STRESSFUL ENVIRONMENTS. TO ADDRESS THIS GAP, THIS PROJECT WILL 1) IDENTIFY CHANGES IN SOIL MICROBIOMES AND COTTON PRODUCTIVITY IN RESPONSE TO COVER CROPPING AND COMPOST APPLICATIONS ACROSS TWO SOIL TYPES, 2) QUANTIFY HOW THESE TREATMENTS AFFECT THE RESISTANCE AND RESILIENCE OF KEY MICROBIAL FUNCTIONS TO SEVERE DROUGHT, AND 3) QUANTIFY HOW THESE TREATMENTS AFFECT SOIL SUPPRESSIVENESS TO A COTTON PATHOGEN. THESE RESULTS WILL REVEAL THE COMBINED AND INDIVIDUAL EFFECTS OF COVER CROPPING AND COMPOST ADDITIONS ON SOIL MICROBIOMES AND COTTON PRODUCTIVITY ACROSS SOIL TYPES, AS WELL AS BETTER DEFINE THE ROLE OF SOIL MICROBES IN COTTON RESPONSE TO DROUGHT AND PATHOGENS.