Effect of micro-irrigation with rainwater catchment on the yield and w ater use efficiency of spring wheat in the northwest of the Loess Plateau

Aid-to-irrigation with rainwater catchment is an efficient measure to assure t he stability and high-yield of crop production in the arid or semi-arid region s ,especially on the Loess Plateau of northern China. In recent years, the resea rches relative to the issue focus on the determination of the aid-to-irrigatio n system with rainwater catchment. The present study was conducted in field plot s at the northwest of the Loess Plateau to evaluate the effect of micro-irrigat ion with rainwater catchment on the yield and water use efficiency (WUE) of spring wheat. In the field experiment, 36 field plots with each area of 15 m2 (3×5 m2) were established and treated with two factors of irrigation method a nd amount of irrigation. The irrigation method as the main-treatment factor was set up with three treatments(pipe-irrigation, drip-irrigation and micro-spri nkle-irrigation). The amount of water as the sub-treatment factor was set up w ith four treatments (0 mm, 22.5 mm 45.0 mm and 67.5 mm). The aid-to-irrigation was given at the jointing stage, booting stage and blooming stage of the spring wheat development. The experiment results showed that (1) the dynamic changes o f soil water in wheat growth period were subjected to the variation of the quant ity at precipitation, irrigation and water consumption. In general, water conten t in soil showed a decrease tendency. Micro-sprinkle-irrigation，especially at the irrigation level of 67.5 mm, significantly increased the water content in t he upper layer of soil (0~40cm); (2) the effect of different irrigation methods on the wheat yield was not significant, however, the yield increase with the inc rease amount of irrigation. The highest yield appeared in the treatments irrigat ed 67.5mm by micro-sprinkle-irrigation. Irrigation led to increase of the ear number per hectare, and decrease of the grain number per ear and 1000 grain weig ht; (3) the WUE of treatments irrigated were higher than that of check (CK); the WUE and water irrigation efficiency (WIE) of micro-sprinkle-irrigation we re highest among the three methods of irrigation; the WUE of the treatments irri gated 67.5mm was highest among the four levels of irrigation amount and the WIE of the treatments irrigated 45.0mm and 67.5mm were higher than other two level s of irrigation amount.he