M Abedinpour - Assistant Professor, Water Engineering Dep., Kashmar Higher Education Institute, Kashmar, Iran
A Sarangi - Associate Professor, Water Technology Center, IARI, New Delhi, India

Optimization of water and nitrogen provides a favorable condition for crop growth and productivity. A field experiment to study the impact of variable water and nitrogen supply on growth, water productivity (WP), irrigation water productivity (IWP) and yield of maize was conducted. The experiment was carried out with four irrigation levels (i.e. rainfed: W1; 50%: W2; 75%: W3 and full irrigation: W4) and three nitrogen fertilization levels (i.e. not fertilized: N1; 75 kg N ha-1: N2; and 150 kg N ha-1:N3). It was observed that varying levels of irrigation and nitrogen resulted in significant difference in yield of maize. Maximum grain yield, biomass, WP and IWP during 2009 were observed for full irrigation W4 and N3 treatment amounting 5.93 t ha-1, 18.15 t ha-1, 12.9 kg mm ha-1 and 15.7 kg mm-1 ha-1, respectively. Moreover, the grain yield and biomass during 2010 was maximum for W4N3 treatment amounting to 5.77 t ha-1, 17.9 t ha-1, but the maximum WP and IWP of 12.6 kg mm ha-1 and 15.5 kg mm ha-1, respectively was obtained for W2N3 treatment. These findings obtained from the experiment will assist in deciding the water and nutrient management strategies of maize crop for enhancing crop productivity under deficit irrigation in the semiarid environment

Deficit irrigation; Water productivity; Nitrogen; Maize