[Desiccation and nitrate accumulation of apple orchard soil on the Weibei dryland].

The study of apple orchard soil on the Weibei dryland showed that high input and high yield not only resulted in soil desiccation, but also induced nitrate accumulation in the soil profile. Generally, the soil layers with accumulated nitrate located in 40 - 260 cm depths, and the maximum nitrate content was 403.4 mg x kg(-1). Owing to the continuous application of nitrogen fertilizer, the accumulated nitrate could hardly be reused in the future, which might lead to environmental pollution. Because the soil storage water could not adjust the water utilization of apple trees, the yield of orchard was affected by precipitation. Therefore, the nitrogen application rate should be reduced, and actions should be taken to improve soil moisture in apple orchard.