Soil moisture utilization depth of apple orchard in Loess Plateau

Effective usage of the orchard soil water storage and regulation is the basis for managements of water and fertilizer. In this study, the neutron probe and oven drying method were used to monitor the soil water content of apple-fruit orchard for nine years in the Loess Plateau, with the aim of determining the soil moisture utilization depth of apple orchard in Loess Plateau. The results show that the soil moisture utilization depth is between 3.0-5.17 m based on the Darcy's law and soil moisture characteristic parameters measured in the trial apple orchard. The soil moisture utilization depth varies with the different location, which is 3.0 m in sunny slop, 4.5 m in shady slop, 3.5 m in semi-sunny slop and 4.0 m in semi-shady slop. Within the range of effective soil water content, the biggest soil moisture utilization depth increases with the soil water content.