THIS PROJECT WILL ENHANCE AGRICULTURAL WATER MANAGEMENT IN SOUTHERN CALIFORNIA DESERTS BY IMPROVING CURRENT UNIFORMLY APPLIED IRRIGATION BY MAINSTREAM GROWERS AND CREATING A PATHWAY TOWARD ADOPTION OF EMERGING SITE-SPECIFIC VARIABLE RATE IRRIGATION (VRI) TECHNOLOGIES IN THE FUTURE. AT FIELD-LEVEL, THIS PROJECT WILL: (I) MAKE SCIENCE-BASED RESULTS OF IRRIGATION RESEARCH TRIALS AVAILABLE TO GROWERS WITH AN OPTIMIZED USER-FRIENDLY COMPUTER TOOL FOR CROP SELECTION AND FULL/DEFICIT IRRIGATION PRACTICES, AND (II) PROVIDE FUNDAMENTAL KNOWLEDGE, HANDS-ON TRAINING AND A COMPUTER TOOL FOR GROWERS TO ADOPT SITE-SPECIFIC VRI SYSTEMS, WHEN APPLICABLE. AT THE CONCEPTUAL-LEVEL, COMPUTER MODELING SIMULATIONS WILL CLARIFY LIMITATIONS AND STRENGTHS OF VRI TECHNOLOGIES TO ADDRESS MOST COMMON FORMS OF FIELD-LEVEL SOIL VARIABILITY USING DRIP/MICRO SPRINKLER IRRIGATION SCENARIOS. AT A LARGER SPATIAL-LEVEL, THROUGH ANALYSIS OF PUBLICLY AVAILABLE HIGH-RESOLUTION (I.E., SUB-FIELD LEVEL) SOIL SPATIAL VARIABILITY AND EVAPOTRANSPIRATION HETEROGENEITY DATA, THE PROJECT WILL EVALUATE THE POTENTIAL IMPLEMENTATION CAPACITY OF VRI SYSTEMS FOR SOUTHERN CALIFORNIA DESERT AGRICULTURE.