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经58县调查,黄土高原土壤水分资源有以下特征:一、土壤持水能力高,其主体质地土壤(轻壤、中壤占80%)的田间持水量一般在19%～22%之间,居于全国中上等水平;二、土壤经常处于低储量水分状态,一般只占到田间持水量的60%～80%和43%～55.9%;三、土壤水分利用率偏低。黄土高原地区,0～5m土层的农田存有剩余有效水为463.16～413.4mm;四、生物利用干层普遍存在,有临时和永久性干层。改善土壤水分条件的措施:1.建立合理的农地、林地、草地配置区;2.建立合理的立体利用土壤水分模式;3.采取相应保墒和耕作措施。
According to the investigation of 58 counties, the soil water resources in the Loess Plateau have the following characteristics: 1. The soil has high water holding capacity, and the field water holding capacity of the soil with the main texture (80% of light and medium soils) is generally between 19% and 22% Living in the country’s upper middle class; Second, the soil is often in low reserves of water, generally accounts for 60% to 80% and 43% to 55.9% of the field water holding capacity; Third, the soil water use efficiency is low. In the Loess Plateau, the remaining effective water in farmland of 0 ~ 5m soil layer is 463.16 ~ 413.4mm; Fourth, dry layer of bio-utilization is ubiquitous, with temporary and permanent dry layer. Measures to improve soil moisture conditions: 1. To establish a reasonable allocation of agricultural land, woodland and grassland; 2. To establish a reasonable use of three-dimensional soil moisture model; 3. To take appropriate moisture and tillage measures.