Variation of soil water content of fixed sand dune at 2014 in the Horqin sandy land

Abstract

The fixed-point observation data of soil water content (SWC) in the growing season (from May to September) of 2014 in the semi-arid region of Horqin Sandy Land was employed to study the characteristics of SWC changes in fixed sand dune. The results showed that: 1) The SWC was relatively high in May. The SWCs in May and June were significantly higher than those in July, August and September, and were significantly different from those in July, August and September. From June to August, the SWC generally showed a decreasing trend. In September, the SWC did not recover obviously and remained at a low level. 2) The SWC was the lowest in the surface layer (0-10 cm), followed by the deep layer (90-150 cm), and highest in the shallow layer (10-90 cm), and there was a large difference among the three layers. The change of SWC with the soil depth showed a reversed S-shaped curve, i.e. “first increase, then decrease, and finally increase again”. The SWC was the highest (3.96%) in the soil layer of 30-50 cm, and the lowest (1.46%) in the soil layer of 0-10 cm. In the soil layer below 110 cm, the SWC showed a little change with the soil depth and tended to be stable.