**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** ABOUT 40% OF THE GLOBAL POPULATION LIVES WITHIN 60 MILES FROMTHECOAST AND ROUGHLY THREE-FOURTHS OF THE LARGE CITIES AROUND THE WORLD ARE ALONG THE COASTLINES. CLIMATE CHANGE ACCELERATES THE SEA LEVEL RISE, SALTWATER INTRUSION AND STORM SURGE CAUSING FLOODING OF SOILS WITH SALTWATER, WHICHIN TURN WILL HAVE AN IMMEDIATEAND SERIOUS IMPACT ON AGRICULTURAL PRODUCTIVITY AND FOOD SECURITY.AS SEA-LEVEL RISE (SLR) CONTINUES, MUCH OF THE ATTENTION OF IMPACT HAS BEEN ON THE SALTWATER INTRUSION (SWI) OF GROUNDWATER AND THE THREAT IT POSES ON THE FRESHWATER RESOURCES IN COASTAL REGIONS. HOWEVER, LIMITED ATTENTION IS GIVEN TO THE IMPACT OF THE LANDWARD MOVEMENT OF SALTWATER BY SURFACE AND/OR GROUNDWATER CONNECTIONS THAT CAN INFLUENCE THE SALINITY OF SOIL IN AGRICULTURAL FIELDS. THE IMPACT OF SLR IS ALSO ON THE SALINIZATION OF DRAINAGE WAYS, INCLUDING NATURAL AS WELL AS MAN-MADE CANALS AND DITCHES, WHICH IN TURN IMPACT SOIL HEALTH AND AGRICULTURAL PRODUCTIVITY AS WELL. THE LAND-USE CHANGES SUCH AS DRAINING THE WETLANDS FOR CULTIVATION RESULTS IN LOWERING THE ELEVATION OF THE LANDSCAPE, AND MORE INLAND WATER CONNECTION THROUGH DRAINAGE DITCHES TO MAINTAIN THE SOIL SUITABLE FOR CULTIVATION. THESE CHANGES WILL CONTRIBUTE TO AN INCREASED RISKOF SALINIZATION OF INLAND SURFACE WATER AND THE SOIL.SWI IS A CRITICAL ISSUE IN FLORIDA, WHICH IS SURROUNDED BY SEAWATER ON THREE SIDES, WHICH HEAVILY DEPENDS ON SHALLOW AQUIFERS AS FRESHWATER SOURCES FOR DRINKING AND IRRIGATION. CHLORIDE CONCENTRATION IN SEAWATER IS 19,400 MG/L, THEREFORE, SWI OF THE SLIGHTEST SCALE CAN EXCEED THE EPA'S STANDARD CHLORIDE CONCENTRATION OF 250 MG/L IN POTABLE WATER. STUDIES BY THE US GEOLOGICAL SURVEY CONFIRMED A SIGNIFICANT INCREASE IN CHLORIDE CONCENTRATIONS BETWEEN 1985 TO 2000 IN SHALLOW AND DEEP AQUIFER WATER SAMPLES IN THE SOUTHWEST AND SOUTHEAST FLORIDA.AS SEA-LEVEL RISE (SLR) CONTINUES, SALINITY DUE TO SALTWATER INTRUSION (SWI) WILL IMPACT SOIL HEALTH AND AGRICULTURAL PRODUCTION. AS SUCH THE SIGNIFICANT THREATS OF SALINITY NECESSITATE MORE WORK TO BE DONE TO BETTER UNDERSTAND ITS IMPACTS ON SOIL HEALTH INDICATOR PARAMETERS AND ASSOCIATED FUNCTIONAL ECOSYSTEM PROCESSES. THIS IS EVEN OF GREATER IMPORTANCE IN AREAS, SUCH AS SOUTH FLORIDA, WHERE THE SURFACE AND GROUNDWATER RESOURCES ARE HYDROLOGICALLY CONNECTED DUE TO THE SHALLOW AND HIGHLY PERMEABLE LIMESTONE SOILS. A BETTER UNDERSTANDING OF THE IMPACTS OF SALINITY DUE TO SWI ON SOIL HEALTH IS CRITICAL TO DESIGN EFFECTIVE MITIGATION STRATEGIES. SOIL HEALTH STATUS COULD BE EVALUATED USING A SET OF MEASURABLE PHYSICAL, CHEMICAL, BIOLOGICAL, AND HYDROLOGICAL ATTRIBUTES. HEALTHY SOIL HAS MULTIFACETED BENEFITS TO ENHANCE AGRICULTURAL PRODUCTIVITY, I.E. REGULATES THE FLOW OF WATER, SERVES AS A SOURCE AND SINK OF NUTRIENTS, AND PROVIDES OPTIMAL BIOLOGICAL AND CHEMICAL CONDITIONS FOR THE TRANSFORMATION OF NUTRIENTS. THIS RESEARCH WILL BE CONDUCTED USING SEAWATER AND MULTI-PRONGED APPROACHES: COLUMN STUDIES, LANDSCAPE MONITORING, AND MODELING FOR IN-DEPTH INVESTIGATION OF THE IMPACTS OF SWI ON SOIL HEALTH, NUTRIENT TRANSFORMATIONS IN SOIL AND SOIL WATER, AND GREENHOUSE GAS (GHG) EMISSIONS WITH A FOCUS ON AGRICULTURAL SOILS. DIFFERENT MANAGEMENT STRATEGIES, SUCH AS THE APPLICATION OF ENGINEERED BIOCHAR, SALT REPELLING HYDROGEL, AND GYPSUM, AND ORGANIC MULCH WILL BE EVALUATED TO MITIGATE THE NEGATIVE EFFECTS OF SWI. IMPROVED UNDERSTANDING OF THE PROCESSES AND IMPACT OF SWI ON SOIL HEALTH WILL ASSIST IN GUIDING POLICY AND DECISIONS REGARDING BEST MANAGEMENT PRACTICES TO MITIGATE THE IMPACTS OF SWI.