青海省海晏县沙柳林土壤水分与土壤水库研究

采用烘干称重法对海晏县城和西海镇附近沙柳林地土壤水分进行研究.结果表明:位于河漫滩上的海晏城附近的沙柳林土壤含水量高,平均含水量为25.1%,土壤水分能够满足沙柳林的正常生长;位于一级阶地上的西海镇沙柳林土壤上部1m范围内含水量较高,平均含水量为19.3%,1m以下含水量很低,有土壤干层发育.这表明,在该区自然降水条件下,除地形低洼、地下水很浅的河漫滩地区之外,土壤水分不能满足人工林正常生长需要.该区沙柳林土壤水分收入小于支出,具有负平衡的特点.该区土壤上部1.0m深度范围内以粉砂为主,孔隙度较高,土质优良,但1.0m以下以粗砂和细砾石为主,土质较差.

Study on soil moisture and soil reservoir of Salix plantation in Haiyan county of Qinghai province

The oven drying weighing method was used to study the soil water at Salix plantation near Xihai town and Haiyan county.Results showed that the soil moisture content was high on the floodplain near the city of Salix plantation,with an average moisture content of 25.1%,so the soil moisture was able to meet the normal growth of Salix plantation.The soil moisture at 1.0 m depth in the upper part of the soil which located at the first terrace near the city of Salix plantation was much higher,with average moisture content of 19.3%.And the soil moisture below 1 m was very low,which was due to the development of soil dry layer.This suggests that soil moisture couldn’t meet the needs of plantation growth under natural conditions of precipitation in the area,apart from low-lying terrain and shallow groundwater in floodplain regions.In this area,the income of soil water was less than its expenditure for Salix plantation,which was a negative balance.The soil at 1.0 m depth was dominated by silt sand with high porosity and excellent quality,but by poor coarse sand and fine gravel below 1.0 m.