半干旱区径流调控工程林草间作模式土壤水分及效益研究

为解决林地土壤干化问题,安定区退耕还林(草)工程实施了以隔坡水平阶为主体的径流调控工程。对隔坡水平阶不同部位2 m土层内土壤水分含量和不同植物措施的保存率、产出效益的调查分析表明,在退耕地实施的隔坡水平阶,大旱之年2 m土层内土壤含水率平均达到6.95%,其中产流区达到7.05%、蓄水区达到6.63%;侧柏林保存率达到92%,多年生紫花苜蓿鲜草产量达到22 417 kg/hm2。以径流调控工程为依托的退耕还林(草)工程实施后,全区森林覆盖率由9.8%提高到11.2%,林草覆盖率达到19.45%,取得了显著的生态、经济、社会效益。

Soil Moisture and Benefits of Intercropping Pattern of Tree and Grass of Runoff Regulation Works in Semi-Arid Area

In order to solve the issue of soil desiccation of forest land,the returning farmland to forest(grass) project of An’ding District carried out runoff regulation and control works by taking level-terrace with slope as the main.It investigated and analyzed the soil moisture within 2 m soil at different locations and preservation rate and output efficiency of different plant measures of level-terrace with slope.The outcomes show that: a) the average soil moisture within 2 m soil in the year of drought reaches to 6.95%,of which,contributing area 7.05% and impounding area 6.63% and;b) the preservation rate of Platycladus orientalis trees reaches to 92% and the fresh yield of perennial Medicago sativa reaches to 22 417 kg/hm2 in the level-terrace with slope where used to be farmland.After carrying out returning farmland to forest(grass) project by relying on runoff regulation and control works,the forest coverage rate of the whole region increases from 9.8% to 11.2% and the coverage rate of trees and grasses reaches to 19.45%,achieving remarkable ecological,economic and social benefits.