MANY LEADING GOVERNMENTAL ORGANIZATIONS INCLUDING THE USDA RECOGNIZE ANTIMICROBIAL RESISTANCE AS A POTENTIAL AND SERIOUS THREAT FOR HUMAN HEALTH. MULTI-DRUG RESISTANT PATHOGENS ARE LARGELY EMERGING BY THE SHARING OF RESISTANCE GENES BETWEEN BACTERIA IN FARM ANIMALS AND HUMAN PATHOGENS THROUGH TRANSMISSIBLE PLASMIDS, WHICH ARE MOBILE GENETIC ELEMENTS THAT CAN CONFER RESISTANCE TO ANTIBIOTICS. HOWEVER, WE STILL DON'T KNOW THE TRAJECTORIES OF THE RESISTANCE PLASMIDS FROM FARMS TO DEADLY HUMAN PATHOGENS, WHICH ENVIRONMENTS PROMOTE PLASMID TRANSFER, AND WHO ARE THE KEY PLAYERS IN THIS DISSEMINATION NETWORK. FERTILIZATION OF SOIL WITH MANURE IS THOUGHT TO SPREAD ANTIMICROBIAL RESISTANCE IN SOILS BY HORIZONTAL TRANSFER OF RESISTANCE PLASMIDS, BUT EVIDENCE IS LIMITED. OUR LONG-TERM GOAL IS TO DETERMINE IF FERTILIZATION OF AGRICULTURAL SOIL WITH MANURE PROMOTES THE ESTABLISHMENT OF RESISTANCE PLASMIDS IN THE SOIL MICROBIOME TO FORM A PERSISTENT RESISTANCE GENE RESERVOIR. HERE WE PROPOSE TOACHIEVE THE FOLLOWING OBJECTIVES, THROUGH A COMBINATION OF NOVEL MOLECULAR METHOD DEVELOPMENT, FIELD AND MICROCOSM STUDIES THAT INVOLVE MULTIDISCIPLINARY APPROACHES FROM ENVIRONMENTAL MICROBIOLOGY, PLASMID BIOLOGY, BIOTECHNOLOGY, BIOINFORMATICS AND STATISTIC MODELING: (1) DETERMINE AND IMPROVE THE LIMITS OF A NEW APPLICATION OF THE HI-C METHOD TO DETECT HORIZONTAL TRANSFER OF RESISTANCE PLASMIDS BETWEEN BACTERIA IN AGRICULTURAL SOILS; (2) DETERMINE THE EFFECT OF MANURE TREATMENT ON THE SPREAD OF A MULTI-DRUG RESISTANCE PLASMID IN THE SOIL SURROUNDING THE ROOTS OF BARLEY; AND (3) DETERMINE THE LONG-TERM EFFECT OF MANURE FERTILIZATION ON THE BACTERIAL RESERVOIRS OF ANTIBIOTIC RESISTANCE GENES AND PLASMIDS IN A REAL AGRICULTURAL FIELD. OUR FINDINGS ARE CRITICAL TO CONTINUED SUSTAINABILITY OF AGRICULTURE AS THEY WILL AID FUTURE DEVELOPMENTS OF STRATEGIES TO SLOW THE SPREAD OF ANTIMICROBIAL RESISTANCE.