黄土高原丘陵沟壑区放牧林草地土壤团聚体性质研究

Soil aggregate properties of grassland and forest during grazing in hilly and gully areas on the Loess Plateau

通过放牧试验的方法,研究土壤团聚体含量和破坏率,以探讨不同放牧强度、不同放牧畜种、不同放牧植被类型条件下表土的团聚体(>0.25 mm)含量和破坏率。结果表明:放牧强度对土壤性质有影响,重度放牧下土壤团聚体含量最小;从畜牧羊种选择来看,绵羊相对于山羊来说对土壤结构破坏较小,土壤中团聚体含量较高;对于不同植被类型,放牧草地的土壤结构要比柠条林地的好。团聚体破坏率分析结果和团聚体含量分析结果基本一致。放牧强度、畜种和植被类型不同均影响着土壤表土的团聚体性质。

With the method of grazing field experiment,we studied the aggregate content and damage rate of the soil,so as to analyze surface soil aggregate（〉0.25 mm） content and damage rate of different grazing intensity,different types of livestock and different types of vegetation.The results show that grazing intensity has certain effect on surface soil structrue and soil aggregate content is the least at heavy grazing intensity.Compared with goat selected as grazing livestock,sheep has less effect on destroying soil structure and has large quantity of soil aggregate.Compared with Caragana korshinkii kom,grazing grassplot has better soil structure.The results of damage rete of aggregate is consistent with that of soil aggregate content.So it is concluded that all categories of grazing intensity,types of livestock and types of vegetation affect the surface soil aggregate nature.