The response of Acala cotton (Gossypium hirsutum L.) in California to a range of applied nitrogen treatments were investigated in a five year, multi-site experiment. Goals of the experiment were to identify crop growth and yield responses to applied nitrogen and to provide information to better assess the utility of soil residual N estimates in improving fertilizer management. Results obtained during this project have shown positive responses to increases in applied N across the 50 to 200 lbs N/acre range in only 16 out of 39 test sites.