Determination of optimum irrigation strategies and effect of drip irrigation system on growth and water use efficiency of pear jujube in Loess Hilly region of northern Shaanxi

The aim of this study is to explore suitable drip irrigation system on the water saving and high yield of pear-jujube from 2009 to 2012 years in the mountain of northern Shaanxi. The treatments consisted of combinations of 5 drip irrigation systems (DP). The irrigation quota of DP-1, DP-2 and DP-3 treatment was 100 m(3) hm(-2), 135 m(3) hm(-2) and 180 m(3) hm(-2), respectively, irrigated 4 times. The irrigation quota of DP-4 and DP-5 treatment was 135 m(3) hm(-2) and irrigated 3 and 2times, respectively; and with no irrigation as the control (C). Results indicated that bearing branch length of jujube, fruit set and yield of different drip irrigation system are significantly better than C (P<0.05). Bearing branch length and yield of DP-3 treatment are reached maximum in 2012, which are 22.0 cm and 16772.8 m(3) hm(-2). And they are increased by 47.7% and 13.2% compared with C, respectively. In addition, the water consumption of different irrigation treatment increases along with the increasing of irrigation amount. And the DP-3 treatment is the highest in different years. The water use efficiency of pear-jujube of low irrigation quota is better than the high irrigation quota. Water use efficiency of 135 m(3) hm(-2) and irrigated 2 times treatment is the best, which is 1.92 m(3) hm(-2). Considering the lack of high annual precipitation, we conclude that DP-5 treatment was the best drip irrigation system in the mountain of northern Shaanxi.