** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.**, UNDERSTANDING THE TRANSPORT AND UTILIZATION OF NUTRIENTS IN CROPS IS CRITICAL FOR SUSTAINING THE GLOBAL FOOD SUPPLY. NITROGEN INPUTS, PARTICULARLY FROM FERTILIZERS, ARE A CENTRAL COMPONENT OF MODERN AGRICULTURAL PRACTICES BUT EXCESS APPLICATION CAN LEAD TO REDUCED FOOD QUALITY. TOOLS THAT PROVIDE INSIGHTS INTO HOW NUTRIENTS ARE TRANSPORTED IN PLANTS WOULD I) GUIDE FERTILIZATION STRATEGIES TO IMPROVE PRODUCTIVITY AND SUSTAINABILITY BY SYNCHRONIZING NITROGEN ADDITION WITH CROP DEMANDS, AND II) INFORM FARMING PRACTICES THAT ADAPT TO THE EFFECTS OF SHORT AND LONG TERM WEATHER VARIABILITY. THE OVERALL OBJECTIVE OF THIS PROJECT IS TO DEVELOP AND COMMERCIALIZE A FIELD-DEPLOYABLE SAMPLING AND MEASUREMENT SYSTEM FOR HIGH TEMPORAL AND SPATIAL RESOLUTION MONITORING OF NITROGEN TRANSPORT AND TRANSFORMATIONS IN LIVING PLANTS. WE PROPOSE TO COUPLE NEEDLE-SIZED PROBES INSTALLED ALONG THE NUTRIENT TRANSPORT PATHS IN PLANTS TO A SENSITIVE AND SELECTIVE MONITOR. A TOOL FOR EASE OF INSTALLATION OF PROBES INTO THE STEM, ROOTS, AND LEAF VEINS OF PLANTS WILL BE DEVELOPED. THE SYSTEM WILL YIELD NONDESTRUCTIVE OBSERVATION OF THE TRANSPORT OF IMPORTANT NITROGEN SPECIES OVER A PLANT'S GROWTH CYCLE.THE PROPOSED RESEARCH AND DEVELOPMENT WILL RESULT IN A MONITORING SYSTEM FOR REAL-TIME, IN SITU MAPPING OF NUTRIENTS. IT WILL BE MARKETED TO THE PLANT SCIENCE COMMUNITY WHICH NEEDS NEW TOOLS TO ADVANCE THE UNDERSTANDING OF NITROGEN CYCLING AND USAGE. THE MARKET IS LARGE DUE TO THE CONTINUED NEED FOR INCREASED CROP PRODUCTIVITY ANDFOOD QUALITY.