** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** ORGANIC DRYLAND WHEAT SYSTEMS IN UTAH ARE HIGHLY DEGRADED AND REQUIRE TWO YEARS OF SOIL-STORED PRECIPITATION TO PRODUCE A CROP OF WHEAT. RESEARCH SHOWS THAT A SINGLE APPLICATION OF COMPOST CAN DOUBLE YIELDS WITH NO LOSS OF QUALITY FOR OVER 26 YEARS. APPROXIMATELY 80% OF THE BENEFITS FROM THE COMPOST ARE NONNUTRITIVE IMPROVEMENTS TO SOIL PHYSICAL HEALTH. WE STILL DO NOT UNDERSTAND WHY CARBON PERSISTS SO LONG IN THESE SYSTEMS, HOW MICROBIAL COMMUNITY COMPOSITION AND FUNCTION ARE AFFECTED BY THE SINGLE COMPOST AMENDMENT OVER TIME, OR C, N AND P CYCLING INTERACTIONS.HERE WE LEVERAGE ESTABLISHED ORGANIC DRYLAND WHEAT FIELD PLOTS, 1 TO 27 YEARS SINCE COMPOST APPLICATION, AND PLOTS AMENDED WITH SLAUGHTER-HOUSE COMPOST, SOFTWOOD-ENRICHED, HARDWOOD-ENRICHED, STRAW IN A SPLIT PLOT DESIGN WITH FEATHER MEAL, TO INVESTIGATE THESE QUESTIONS. WE USE A CEMENTED LAYER TO STUDY C ACCUMULATION AT DEPTH. GENOMICS AND ENZYME ASSAYS ARE USED TO INVESTIGATE CHANGES IN MICROBIAL COMMUNITY AND FUNCTION. SIMULTANEOUS C, N AND P ANALYSES ARE USED TO TEASE APART NUTRIENT INTERACTIONS. THE RESEARCH WILL IMPROVE OUR UNDERSTANDING OF C ACTIVITY AND PERSISTENT IN DRYLAND SYSTEMS AND INFORM GROWERS HOW BEST TO ECONOMICALLY AMEND THEIR SOILS TO ACHIEVE SOIL HEALTH GOALS