Water Use Efficiency and Water Production Function of Corn under Full and Deficit Irrigation in a Cold Semi-arid Environment

In this study, corn (Zea mays L.) yields measured in the fields during eight years from 2005-2006 to 2012-2013 were compared with those simulated by the Agro-ecological Zone method under cold semi-arid environment. The potential yield (Ym) of corn was 10 430 kg ha-1 with a net water for irrigation of 6 180 m3 ha-1. Water-production function for corn was acquired with application efficiency scenarios from 100% to 40%. To produce a potential yield of corn, irrigation water requirement was 6 180, 6 867, 7 725, 8 829, 10 300, 12 360, 15 450 m3 ha-1 under water application efficiency of 100, 90, 80, 70, 60, 50 and 40%, respectively. Results showed that measured yield ranged from 5 784 to 7 026 kg ha-1 per ha with an average of 6 404 kg ha-1. Water applied to produce corn averaged 10 567 m3 ha-1. The water use efficiency (WUE) averaged 0.61 kg m-3 during eight years and water application efficiency was 51.2% in corn farms. It is suggested that deficit irrigation could be applied to enhance water use efficiency in corn production under cold semi-arid environment