阴山北麓不同用地方式下春季土壤可蚀性研究

阴山北麓位于中国北方农牧交错带内,此区属于生态环境脆弱地带,加之人类对土地资源的不合理利用,导致了严重的土壤风蚀问题,土壤可蚀性是影响土壤侵蚀大小的重要因素之一。本文通过对该区域土壤取样及室内理化分析,结合采样点的地表物质组成、植被覆盖度及土壤有机质含量等因素,分析了其潜在可蚀性。研究结果表明:阴山北麓草地的平均土壤潜在可蚀性最小,为63.82%,耕地的平均土壤潜在可蚀性最大,为66.05%,灌丛和林地居于其中,分别64.58%和64.88%。耕地的平均可蚀性>林地的平均可蚀性>灌丛的平均可蚀性>草地的平均可蚀性。随着春季温度的升高和不断的风蚀,土壤可蚀性也发生相应的变化,但这种变化并不是持续的,当温度达到一定程度时,土壤温度和湿度环境发生了变化,土壤潜在可蚀性反而降低,表现为第二次采样的土壤可蚀性>第三次采样的土壤可蚀性>第一次采样的土壤可蚀性。土地利用方式不同,土壤表层的理化性质、地表状况也会产生一定的差异,从而导致了表层土壤的潜在风蚀性不同。人类活动在土地利用过程中起主导作用,它是叠加在自然因素之上的影响土壤潜在风蚀性的人为因素。所以,应加强对耕地的保护,退耕还林草,减小其潜在风蚀性。

Spring soil erodibility for different land use patterns in the north piedmont of the Yinshan Mountains

The north foot of the Yinshan Mountain lies in farming and grazing transitional belt,where is fragile region of ecology environment in north China.In addition,the irrational land use caused serious wind erosion.Soil erodibility is one of the important factors effecting the soil erosion.In this paper,the soil is investigated and sampled in field in 2004 from March to April in the north foot of the Yinshan Mountain.Wind erosion driving factors including the compound of surface material,the rate of vegetation coverage and the content of organic matter are combined in the samples and the soil potential erodibility is analyzed.It shows that the soil potential erodibility of grassland is 63.82% which is the smallest and the soil potential erodibility of cultivated land is 66.05% which is the biggest in the north foot of the Yinshan Mountain.The soil potential erodibilities of bush and woodland are 64.58% and 64.88% separately which are between the soil potential erodibility of grassland and the soil potential erodibility of cultivated land.The average changing of soil erodibility in different land use in the three samplings is cultivated land > woodland > bush > grassland.With wind erosion and the increasing temperature in spring,soil erodibility altered correspondingly.However,the change is not proceeding.Soil erodibility decreases when temperature reaches a certain degree and soil temperature and humility conditions change.The total change process of the soil erodibility is the soil erodibility on the second sampling > the soil erodibility on the third sampling > the soil erodibility on the first sampling.In different ways of land use,the properties of soil surface and condition bring about a great difference to a certain extent,which lead to the difference of the potential erodibility of soil surface.Human activities have decisive effects on land use,which are the humane factors overlapping the natural factors.The soil erosion is more serious in the cultivated land than that in other places.Hence,in the process of land use,the factors influencing wind erosion should be considered and the relation between human and natural should be coordinated in order to decrease the wind erosion in a large degree.The protection of the cultivated land should be reinforced and the policy of returning cultivated land to woodland and grassland should be strengthened further in order to reduce the soil potential erodibility.