**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** NUTRIENT AND WATER MANAGEMENT ARE TWO OF THE MOST CHALLENGING ISSUES TO THE SUSTAINABILITY OF US AGRICULTURE. WE SEEK TO SIMULTANEOUSLY ADDRESS THESE PROBLEMS THROUGH DEVELOPMENT OF AN INNOVATIVE TECHNOLOGY THAT CAN (I) RECOVER 90% OF THE NUTRIENTS IN PIG MANURE AS CHEMICALLY-BALANCED STRUVITE AND POTASSIUM STRUVITE FERTILIZERS AND (II) TREAT BRACKISH GROUNDWATER TO IRRIGATION-QUALITY STANDARDS WITH TOTAL DISSOLVED SOLIDS LESS THAN 1400 MG L-1. THE NUTRIENT RECOVERY SYSTEM WILL OPERATE BY DONNAN DIALYSIS, WHICH USES ION EXCHANGE MEMBRANES TO SELECTIVELY SEPARATE IONS WITHOUT ELECTRICITY, SPECIALIZED MICROBIAL CONSORTIA, OR EXPENSIVE CHEMICALS. THE MAIN INPUT TO DONNAN DIALYSIS SYSTEMS IS SALT, WHICH WILL BE SUPPLIED FROM BRACKISH GROUNDWATER TO NOT ONLY OFFSET OPERATING COSTS, BUT ALSO PRODUCE LOW-SALINITY WATER FOR IRRIGATION. TO IMPROVE THE RATE OF NUTRIENT RECOVERY, WE WILL GENERATE NOVEL HOLLOW-FIBER CATION AND ANION EXCHANGE MEMBRANES WITH HIGH SURFACE AREA-TO-VOLUME RATIOS. SELECTIVITY AND DIFFUSION COEFFICIENTS FOR NUTRIENTS IN THE HOLLOW-FIBER ION-EXCHANGE MEMBRANES WILL BE COMPREHENSIVELY ASSESSED FOR DIFFERENT CONDITIONS, AND THESE PARAMETERS WILL BE USED TO CONSTRUCT A FULLY-AUTOMATED PILOT-SCALE REACTOR THAT CAN ACHIEVE 90% NUTRIENT RECOVERY WITHIN 12 H. ACHIEVING THESE GOALS WILL ADVANCE ON-FARM NUTRIENT MANAGEMENT, CLOSE AGRICULTURAL NUTRIENT CYCLES, PREVENT WATER POLLUTION, AND GENERATE SLOW-RELEASE FERTILIZERS AND ALTERNATIVE IRRIGATION WATER SOURCES FOR SUSTAINABLE FOOD PRODUCTION. FOR THESE REASONS, THE PROPOSED RESEARCH WILL HELP TO SUSTAIN WATER AVAILABILITY AND SOIL HEALTH TO 2050 AND BEYOND AND NAVIGATE CHALLENGES FROM GROWING POPULATION, FINITE RESOURCES, ENVIRONMENTAL QUALITY, CLIMATE VARIABILITY, NUTRITIONAL SECURITY, AND FOOD SAFETY.