**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** ECOLOGICAL DIFFERENCES ACROSS COVER CROP SPECIES AND THEIR EFFECT ON SOIL PROCESSES SUCH AS SOC ACCRUAL, AGGREGATE FORMATION AND P MOBILIZATION OFFERS FARMERS THE OPPORTUNITY TARGET SPECIFIC SOIL HEALTH BENEFITS THROUGH COVER CROP CHOICES. THIS LITERATURE HAS BEEN DIVIDED BY DISCIPLINE AND REQUIRES A BRIDGING APPROACH WITH SYSTEMATIC STEPS AS PROPOSED HERE, TO SCREEN PROMISING COVER CROP CANDIDATES, FOLLOWED BY AN ON-FARM PROOF OF CONCEPT TO ASSESS FARMER PERSPECTIVES, ALONG WITH THE CURRENT STATUS OF COVER CROP-P AND SOIL P POOLS ON-FARM. FINALLY, THERE IS NEED TO UNDERSTAND LONG-TERM MANAGEMENT EFFECTS ON SLOW SOIL P BIOGEOCHEMICAL PROCESSES AND THE EFFECTS OF DIVERSIFIED MANAGEMENT VS FERTILIZER INTENSIVE, SIMPLIFIED CROPPING SYSTEMS. THIS WILL BE ASCERTAINED BY CHARACTERIZING SOILS FROM LONG-TERM FIELD CROP EXPERIMENTS, UTILIZING ISOTOPIC APPROACHES ALONG WITH ENZYMATIC AND ORGANIC MATTER POOL FRACTIONATION, WHICH WILL BE COMPARED TO CLASSIC SOIL P HEDLEY FRACTIONATION. OUR PROJECT WILL PRODUCE NEW, INTEGRATED KNOWLEDGE ON SOIL P FERTILITY AND COVER CROPS EFFECTS, TO PROMOTE SOIL HEALTH. NOTABLY, THIS RESEARCH WILL FEED DIRECTLY INTO COVER CROP DECISION TOOLS FOR SOIL HEALTH, WHICH ARE IN WIDE USE TODAY.