定西市安定区退耕还林地径流聚集工程的土壤增墒效果

目的]分析退耕还林地径流聚集工程的土壤增墒效果,为改善林地土壤水分供给研究提供依据。方法]通过对甘肃省定西市安定区退耕还林地中径流聚集工程形式和造林模式的调查研究,分析半干旱地区隔坡水平阶、隔坡反坡台、正方形聚流坑、燕尾式聚流坑不同整地方式下林地增墒效果及其林草的生长发育状况。结果]径流聚集工程具有明显的土壤增墒效果,在径流聚集工程作用下乔木树种单株水分供给总量达2.54~4.29m~3/(株·a),灌木树种单株水分供给总量达1.42~1.79m~3/(株·a),2m土层内含水率达到8.76%~11.40%,土壤水分基本满足了林草植被的正常发育需求,林草生长旺盛。结论]在同类地区的人工林建设中可选择适宜的树种与相应的径流聚集工程结合,改善林地土壤水分供给状况。

Effects of Runoff Gather Engineering on Soil Moisture Conservation in Forest Land Converted from Cropland in Anding District of Dingxi City

Objective] To analyze the effects of runoff gather engineering on soil moisture conversation in afforestation land converted from cropland in order to provide the basis for improving soil water supply in planted forest.Methods] With an intensive survey on the runoff gather engineering and afforestation types, we investigated soil moisture conservation and growth and development of tree and grass under different site preparation practices including slope-separate flat terrace(SSFT), slope-separated reversing sloping terrace(SSRST), cone-shape focused fluid pit(CFFP), Swallow-tail-shape focused fluid pit(SFFP) in the region of returning farmland to forest land in Anding district of Dingxi City, Gansu Province.Results] The runoff gather engineering increased soil moisture and improved water supply to the plants greatly. The total water supply for individual tree reached to 2.54~4.29 m³/a, and it reached to 1.42~1.79 m³/a for an individual bush. Soil moisture within the 2 m soil depth varied from 8.76% to 11.40%, which satisfied the water demand for the growth and development of trees and grasses.Conclusion] Feasible runoff gather engineering practices combined with suitable tree species, can improve soil water supply in planted forest.