** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** AGRICULTURE MUST ADAPT TO THREATS FROM CLIMATE CHANGE, INCLUDING VARIABLE PRECIPITATION AND CHANGES IN WEED PRESSURE. THIS PROJECT EXAMINES THE INDIVIDUAL AND COMBINED EFFECTS OF MULTIPLE, COMPLEMENTARY AGROECOLOGICAL PRACTICES: STRATEGIC MANIPULATION OF CROP ROW ORIENTATION AND SPACING TO MAXIMIZE LIGHT INTERCEPTION BY THE CROP; INTERSEEDING COVER CROPS TO INCREASE SPECIES DIVERSITY AND TOTAL PHOTOSYNTHESIS; AND THE USE OF TERMINATED COVER CROP MULCHES TO CONSERVE SOIL MOISTURE AND SUPPRESS WEEDS. THIS PROJECT WILL ALSO UTILIZE AN EXTENSIVE ON-FARMDATASET OF MORE THAN 400 SITE-YEARS OF GEOSPATIALLY REFERENCED INFORMATION ACROSS 28 US STATES TO QUANTIFY THE EFFECTS OF CROP ROW ORIENTATION ON CROP YIELD AND OTHER AGRONOMICALLY RELEVANT VARIABLES. TO QUANTIFY THE EFFECTS OF EACH OF THESE AGRICULTURAL PRACTICES ALONE AND IN CONJUNCTION WITH ONE ANOTHER, WE WILL CONDUCT TWO MULTI-YEAR FIELD EXPERIMENTS. WE WILL MEASURE RELEVANT SHORT-TERM AGRONOMIC VARIABLES INCLUDING YIELD, WEEDS, SOIL WATER, PLANT PHYSIOLOGICAL RESPONSES, AND CARRYOVER EFFECTS ON THE SUBSEQUENT CROP AND SOIL HEALTH INDICATORS. TO GAIN A GREATER UNDERSTANDING OF THE POTENTIAL MECHANISMS UNDERLYING THE EFFECTS OF LIGHT MODULATION ON CROPS RESULTING FROM DIFFERING ROW ORIENTATIONS AND SPACING, WE WILL MEASURE PHOTOSYNTHETICALLY ACTIVE RADIATION, SOIL MOISTURE, AND TEMPERATURE CONTINUOUSLY. THIS PROJECT WILL ILLUCIDATE GENERAL PRINCIPLES ABOUT THE FUNCTION, PROPERTIES, AND PERFORMANCE OF AGRICULTURAL PRODUCTION SYSTEMS AND INVESTIGATE HOW MULTIPLE MANAGEMENT COMPONENTS OF AGRICULTURAL PRODUCTION SYSTEMS CAN BE INTEGRATED TO ENHANCE SOIL-CROP-ATMOSPHERIC PROCESSES AND AGRICULTURALRESILIENCE TO STRESSORS INCLUDING THOSE EXACERBATED BY CLIMATE CHANGE.