**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** BACKGROUND. PER- AND POLYFLUOROALKYL SUBSTANCES (PFASS) HAVE BEEN FREQUENTLY FOUND IN AGRICULTURAL IRRIGATION WATER AND SOILS. IRRIGATION WITH PFASS-CONTAMINATED WATER COULD CAUSE THE ACCUMULATION OF PFASS IN FIELD CROPS DURING PLANT GROWTH. THE SUBSEQUENT DIETARY CONSUMPTION OF PFASS-TAINTED AGRICULTURAL PRODUCT COULD IMPACT HUMAN AND ANIMAL HEALTH. HUMAN CONSUMPTION OF CROPS/VEGETABLES SHOULD BE CONSIDERED AN IMPORTANT EXPOSURE PATHWAY TO PFASS, WHICH IS COMPARABLE (IF NOT MORE IMPORTANT THAN) TO THE DRINKING WATER EXPOSURE PATHWAY. THEREFORE, IN ORDER TO IMPROVE FOOD SAFETY AND HUMAN HEALTH WHILE MAINTAINING THE PROFITABILITY OF AGRICULTURAL PRODUCTION, EFFECTIVE AND LOW-COST SOIL MANAGEMENT STRATEGIES ARE CRITICALLY NEEDED TO MITIGATE THE TRANSFER OF PFASS FROM AGRICULTURAL IRRIGATION WATER TO FRESH PRODUCE.GOAL AND HYPOTHESIS. THE OVERARCHING GOAL OF THIS PROJECT IS TO DEVELOP PRAGMATIC MANAGEMENT PRACTICES THAT CAN IMMOBILIZE PFASS IN SOILS, REDUCE THEIR BIOAVAILABILITY TO PLANTROOT UPTAKE, AND MITIGATE THEIR ACCUMULATION IN AGRICULTURAL PRODUCE. IRRIGATION WITH PFASS-CONTAMINATED WATER INTRODUCES PFASS INTO SOILS, TRANSPORT WITH WATER TO PLANT ROOT ZONE, AND ACCUMULATE IN AGRICULTURAL CROPS GROWN IN THE SOILS. IN THIS PROJECT, WE PROPOSE TO ELUCIDATE THE FATE AND TRANSPORT OF PFASS IN SOIL-WATER-PLANT SYSTEMS, AND INVESTIGATE THE FEASIBILITY TO INTERFERE WITH THE TRANSPORT OF PFASS TO FOOD CROPS USING SORBENT AMENDMENTS. THE CENTRAL HYPOTHESIS IS THAT SOIL PORE WATER IS THE MAJOR CARRIER BY WHICH PFASS ARE MOVED FROM SOIL TO PLANT ROOT ZONES. SORBENT AMENDMENTS COULD EFFECTIVELY IMMOBILIZE PFASS IN SOILS AND REDUCE THEIR BIOAVAILABLE FRACTIONS TO PLANT ROOT UPTAKE.SPECIFIC OBJECTIVES. (1) EVALUATE PFASS SORPTION, TRANSPORT AND IMMOBILIZATION IN SOILS AMENDED WITH LAYERED DOUBLE HYDROXIDE (LDH) AND AL-, FE-MODIFIED BIOCHARS. (2) DETERMINE THE BIOAVAILABILITY OF PFASS TO PLANT UPTAKE FROM SOILS AMENDED WITH LDH AND MODIFIED BIOCHARS. (3) VALIDATE THE TO-BE-DEVELOPED MANAGEMENT TO MITIGATE THE ACCUMULATION OF PFASS IN FIELD CROPS.APPROACHES. WE WILL INTEGRATE LABORATORY EXPERIMENTS OF PFASS SORPTION AND TRANSPORT IN SOILS, GREENHOUSE POT EXPERIMENTS AND FIELD PLOT TRIALS OF PLANT UPTAKE OF PFASS, AND ADVANCED LC-MS/MS ANALYSIS THAT CAN QUANTIFY PFASS AT ENVIRONMENTALLY RELEVANT CONCENTRATIONS TO UNDERSTAND THE MECHANISTIC DETERMINANTS OF PFASS MOVEMENT FROM SOIL TO PLANT. PFASS SORPTION BY SOILS, PLANT PHYSIOLOGICAL ACTIVITIES AND SOIL PORE WATER MOVEMENT ARE THE CRITICAL PROCESSES THAT WILL BE STUDIED FOR THEIR IMPACTS TO UPTAKE AND ACCUMULATION OF PFASS IN CROPS. WE WILL EXAMINE WHETHER PFASS CONCENTRATION IN SOIL PORE WATER COULD BE SIGNIFICANTLY REDUCED IN THE PRESENCE SOIL AMENDMENTS LDH AND AL- FE-MODIFIED BIOCHARS, AND WHETHER THIS APPROACH COULD EFFECTIVELY LEAD TO THE MITIGATION OF PFASS UPTAKE AND ACCUMULATION IN FIELD CROPS.EXPECTED OUTCOME AND POTENTIAL IMPACTS. THIS PROJECT WILL ADVANCE THE MECHANISTIC KNOWLEDGE ON PFASS INTERACTION WITH SOILS, LDH AND BIOCHARS, TRANSPORT FROM SOILS TO PLANT, AND PLANT ACCUMULATION RELATED TO PFASS PROPERTIES AND PLANT PHYSIOLOGICAL ACTIVITIES. THESE INDIVIDUAL PROCESSES WILL BE INTEGRATED TO EVALUATE AND MODEL THE FATE AND TRANSPORT OF PFASS IN SOIL-WATER-PLANT SYSTEMS. THE RESULTS WILL PROVIDE THE FOUNDATION ON USING LDH AND MODIFIED BIOCHARS AS SORBENT AMENDMENT TO IMMOBILIZE PFASS IN SOILS WHILE MITIGATING THE ACCUMULATION OF PFASS IN AGRICULTURAL CROPS. THE RESULTS WILL PROVIDE GUIDELINE FOR GENERATING SCIENCE-INFORMED MANAGEMENT PRACTICES WITH RESPECT TO SORBENT AMENDMENT, AND IRRIGATION WITH PFASS-CONTAMINATED WATER. THESE OUTCOMES WILL LEAD TO ACTIONABLE SOLUTIONS THAT ENSURE THE SUSTAINABLE AGRICULTURAL ENVIRONMENT AND SAFE FOOD PRODUCTION.