Water and Nitrogen Interactions in Deficit Drip Irrigated Cotton

Multiple years of deficit drip irrigation trials were conducted in a clay loam soil at the University of California West Side REC in the western San Joaquin Valley.   Deficit irrigation levels ranged from mild to moderate, with most treatments emphasizing gradually intensifying water deficits during later boll filling and maturation stages. Nutrient uptake (mostly N, P, K) was evaluated at two growth stages as a function of irrigation treatment in two Upland and one Pima cotton cultivar in the study.  Water stress severity and timing impacts on growth and yield responses will be described.