Abstract:In order to investigate the relationships between tree crown size and water consumption of rain-fed jujube plantations, soil moisture under different conditions (natural planting, high-density dwarfing, stem-cutting, extreme dwarfing and pruning with different intensities) were measured by using the CNC100 neutron gauges, meanwhile, water balance method was used to calculate the water consumption and water use efficiency of above-mentioned jujube plantations. Results showed that compared with natural plantation, high-density dwarfed jujube trees reduced annual water consumption of 6.54mm and water consumption depth of 13.3cm, respectively. Moreover, it increased the water use efficiency to 1.8kg/m3 (the lowest for natural jujube plantation was 2.1kg/m3). The soil moisture restoration of 12 years old cutting stem jujube plantation reached 460cm depth in the third year (153.3cm per year on average), which was 3.41 times faster than the formation of soil dry layer. Extremely dwarfed jujube with half of normal crown size decreased the water consumption by 25% and improved the water use efficiency by 1.26 times of natural jujube plantation, respectively. Pruning is an effective approach to improve soil water status and water use efficiency in jujube plantation because of the close relationship between crown size and jujube water usage. Furthermore, the reasonable pruning intensity, which aimed to obtain high yield and water use efficiency, should be determined based on local rainfall considering its high variability in the semi-arid Loess Plateau.