Effects of water deficit in different growth stages and N fertilizer levels on maize growth and water use efficiency in Northwest China

Soil water and nutrients are key factors for plant growth and development as they are involved in many processes in plants. The purpose of this study was to investigate the effect of water deficit in different growth stages on maize growth and water use efficiency. Randomized block design with three replications and the treatments consisted of three levels of irrigation and three levels of N fertilizer were used. Three irrigation levels were W1 (water deficit at seedling stage), W2 (water deficit at jointing stage), W3 (water deficit at filling stage) and nitrogen (N) fertilizer levels were F1 (0.1 g pure N kg(-1) soil), F2 (0.2 g pure N kg(-1) soil) and F3 (0.3 g pure N kg(-1) soil). The control treatment was composed of full irrigation and without N fertilizer application (CK). The results indicated that the interactions between irrigation and N fertilizer were important for shoot dry matter and root dry matter. The ranking of N fertilizer treatments, from high to low accumulations of root and stem-leaf dry matter averages, was F1>F3>F2. The falling of accumulation of nitrate in plants was mainly attributed to the proper enhancing ammonium reduced the adsorptive capacity of nitrate. Water deficit at different growth stages were significantly increase the total N content of stem-leaf. In conclusion, the maize can repair itself so they stop growing when water deficit at seedling stage, but do not die. They simply resume growth later when the water supply is plenty.