Field experiments were conducted in 2006 and 2007 at the University of Arizona Maricopa Agricultural Center investigating soil-plant-water relations in an irrigated cotton (Gossypium hirsutum L.) production system. Current guidelines for the management of irrigation for cotton production systems in the desert Southwest utilize parameters that have not been thoroughly validated. The objective of this project was to develop an accurate water balance in a furrow-irrigated cotton production system and evaluate the accuracy of the crop coefficients that are currently available through the University of Arizona Meteorological Network (AZMET). Measurements of water application rates were taken with each irrigation event. In-season soil-water measurements were made prior to and immediately following each irrigation event by use of neutron attenuation to a depth of four feet (approximately 120 cm). Soil-water depletion rates were compared to crop ET estimates provided by AZMET. In-season crop monitoring was conducted and final lint yield was determined. Fiber quality was determined by HVI analysis. Results provide a thorough characterization of the soil-plant system under study and indicate soil-water depletion rates compare favorably with the crop ET estimates.