Study On Soil Quality Of Slope Micro-topography In North Shaanxi

In the Loess Plateau in northern shananxi, the wavy change of terrain in the hilly-gully region consequently forms the micro-topography of varying shapes and sizes, at the same time, causes the differences in physical property of the local soil on slope surface.It is these differences that result in the distinction of growth condition of the vegetation.What's more,the joint action of both terrain and surface coverage affects the distribution and movement of the physical and chemical properties of the soil, forming the unique habitat condition for various micro-topographies.Based on the actual situation of the hilly-gully region, the research studied the micro-topography on the loess slope. divideing it into five types such as ephemeral gully, gully, collaps, eplatform and scarp.In this study,the different qualities of soil in micro-topography are analyzed to explore the evolution of soil in the process of revegetation.The results are as follows:1.According to the study on the soil quality of the different micro-topographys in natural recovery, it is found that different micro-topography has different physical and chemical properties of soil. Among them,the soil quality of collapse is the best, gully,platform and ephemeral gully are the worse, scarp is the worst. The vegetation of collapse and gully has been well restored and even appeared Maru Zi, Caragana and some other small shrubs in those years. The soil quality of scarp is worst, so are the vegetation of coverage and height.2.Under the artificial afforestation condition,the soil quality of different micro-topography is distinguished from that of the natural recovery. Under the artificial afforestation condition,the soil quality of gully and platform is the best,however,The soil quality of the collapse,which is the best performer in natural recovery,is poorer than the other terrains.3.Through the comparison of different recovery modes, in three soil layers,the effection of the natural recovery and the artificial afforestation is similar. The soil quality of ephemeral gully in natural recovery is better than that in artificial afforestation. Gully in the 0-20cm soil layer achieves better results in natural recovery than that in artificial afforestation. However, it is just opposite in the 20-40cm and 40-60cm. The natural restoration of Collapse performs better whether in physical property,chemical property or enzyme activity in the 0-20cm,20-40cm and 40-60cm and the balance is relatively large. Platform receives effect slightly better in natural recovery in the 0-20cm but the artificial one wins with small difference in the 20-40cm and 40-60cm.Both of natural restoration and artificial afforestation play an equal role in progressing the soil quality for Platform, but artificial afforestation is conducive to improve the soil quality of deeper layers. The natural recovery of scarp reaches greater improvement in the 0-20cm and 40-60cm than the other one, but the balance is extremely small. In 20-40cm, the artificial beats the natural with narrow gap,which turns out that the scrap is in the same case of the platform.4.Under the conditions of natural recovery, Soli quality was affected by dfferernt type of their restored years and vegetation. After 50 years of natural recovery, the structure type of trees brushes and graaaes was formed, and the soil quality of physical and chemical properties was much greater than of 11 years',with soil recovery developing from the shallow soil layer to the deeper one.5.The study on soil quality The study on the soil quality cllocated by different vegetation shows that,the soil quality restores perfectly in chinese pine fores,hippophae rhamnoides forest and mixed forest of pine and hippophae rhamnoides.On the contrary,the soil in apricot and hippophae rhamnoides forest along with the vegetation lacking of recovery measures is relatively poor.At layer 0-20cm,20-40 cm and 40-60cm, chinese pine forest is the best,so in the early vegetation restoration, recovery can be promoted with its help.Considering the healthy and sustainable development of forest in the future, some other species can be planted to fit for the different stage of restoration.In conclusion,different approaches corresponding to the specific circumstances can be adopted to restore vegetation in the Loess Plateau. The soil quality of gully and collapsed under the natural recovery is better than in artificial afforestation, ephemeral gully(EG),platform and scarp is not significant. During the vegetation recovery, platform and ephemeral gully(EG) can be taken artificial afforestation, because of the easy manual,planting trees and grass; Scarp suggests natural recovery,and it will save human,material and financial resources. In the choice of the type of vegetation collocation, chinese pine,hippophae rhamnoidesand or the mixed mode of chinese pine and hippophae rhamnoidesand can be taken into consideration.