黄土丘陵沟壑区草地土壤持水、供水性能比较

Comparison of Soil Water-holding and Water-supplying Ability of the Different Grassland in Loess Hilly Region

对黄土丘陵沟壑区5种典型草地表层土壤的结构、持水性能及供水能力进行了测定,结果表明:沙打旺群落持水能力最强,其次为百里香群落,再者为长芒草群落和铁杆蒿群落,大针茅群落最低;百里香群落的土壤供水能力最大,大针茅群落最小,沙打旺群落、长芒草群落及铁杆蒿群落次之;土壤失水速度为大针茅群落>铁杆蒿群落>百里香群落>沙打旺群落>长芒草群落。百里香群落草地土壤饱和含水量最高,大针茅群落最低。田间持水量及有效水含量随>0.25mm水稳性团聚体含量增加而提高。饱和导水率为:百里香群落>沙打旺群落>长芒草群落>铁杆蒿群落>大针茅群落,与>0.25mm水稳性团聚体含量成正相关。与大针茅群落等其它草地相比,沙打旺群落和百里香群落土壤条件较好,可促进土壤水分的入渗、保留及供给植被利用,提高该区的水土流失防治速度,促进生态环境的改善。

By comparison of soil structure, soil water-holding and water-supplying ability of five typical grasslands in loess hilly and gully region including Artemisia gmelinii, Thymus mongolicus, Astragalus adsurgens Pall, Stipa bungeana and Stipa gtandis, the result indicated that the supplying water of Thymus mongolicus was highest than other grasslands, and that of Stipa gtandis was the lowest, so was the trend of soil holding water. But the soil losing water of Stipa gtandis ranked the first, then followed by Artemisia gmelinii,Thymus mongolieus and Astragalus adsurgens Pall. However, Stipa bungeana was at the bottom. Thymus mongolieus had the highest saturated moisture, and Stipa glandis＇s was lowest. Meanwhile, it was also indicated that the field capacity and available moisture capacity was increasingly added with the increase of amount of 〉0.25 mm aggregate. The saturated hydraulic conductivity, positive ton＇elation with the amount of 〉0.25 mm aggregate, was ranged in order from the highest ones to lowest as follows： Thwnus mongolieus , Astragalus adsurgens Pall, Stipa bungeana, Artemisia gmelinii and Stipa gtandis. The community of Astragalus adsurgens Pall and Thymus mongolicus had priority, whose soil condition was favorable, and could promote water to infiltrate, hold water and transport them to vegetations in the ground. So the soil and water loss was controlled well and ecological environment was improved.