The Research Of Soil Properties In Rocky Desertification Area With The Different Land Use Patterns

Karst rocky desertification is one main ecological environment problem in China. karst areas has low background values in natural environment. Due to fragile ecology, the unreasonable use and the human activity intervention to different lands will cause vicious cycle of ecological environment. Currently, stony desertification has become one of the research hot topics in field of geography at home and abroad. To explore the influence of different ways of land use on physical and chemical properties and characteristics of soil in stony desertification areas and analyze the response of various soil factors to stony desertification has important theoretical significance and reference value for helping karst areas to find reasonable ways of land use, promote ecosystem restoration of stony desertification, and finally achieve ecological sustainable development.Regarding main issues in the ecosystem environment of karst mountainous area, the article, with the basic properties of soils under different utility patterns in typical stony desertification as the main contents, by combining field monitoring with indoor experimental analysis, select two demonstration plots with different grades of stony desertification as the research areas: moderate–intense Guanling-Zhenfeng huajiang canyon demonstration plot and potentialmild Qingzhen Hongfeng lake demonstration plot. Then the article investigates the land utility by contrasting the land physicochemical properties under different land utility patterns in karst canyon area and karst basin to analyze the soil’s basic characteristic index under different land utility patterns and discuss the influence of human intervention on soil environment in the process of stony desertification treatment. Main research results are as below:(1)Through the analysis on soil physical properties under different land utility patterns in two demonstration plots, we get the result showing that :(1)Water content in surface soil changes a lot, and it changes from intensely to steadily from to bottom after the depth of 10 cm of the soil layer. The soil moisture in arable layer moves frequently.(2) Agricultural development,eco-environment and soil water retention in karst basin area is better than karst canyon area. Forest conservation can effectively preserve soil and water. Soil water storage property is better when planting grass under the trees and in scrub-grassland model. Soil water retention is higher under the measures of stony desertification treatment. Compared with traditional arable land, economic fruit forest is the main measure to preserve soil and water and advantageous in controlling soil loss and improving eco-environment.(3)It can be seen from the analysis on soil water retention property that, there is litter human intervention in forest conservation, and soil water retention is better than arable land, grass land, and economic fruit forest zone. Thinness of soil layer in intense rocky desertification area has led to the low water retention and poor water storage capacity.(4)There was no significant difference with soil bulk density in the two demonstration areas,The range of soil bulk density in huajiang canyon demonstration plot and Qingzhen Hongfeng lake demonstation Plot are in 0.71g/cm3——1.47g/cm3 and 0.61g/cm3— — 1.27g/cm3,respectively.(5) Under different land utility patterns, there are notable differences in soil pore space change. Soil permeability is higher under the land utility pattern after desertification control.(2)Comparing soil physical properties under different land utility patterns in two demonstration plots, we get the result:(1)Total nitrogen contents of most sample land in two research areas are lower than the national average value, just 1/3-2/3 of the national average value.(2)Total potassium and ph value in soil of Huajiang demonstration plot is higher which is bad for vegetation growth. Qingzhen demonstration plot is on the contrary.Forest and grass land can provide basic nutrient for soil.(3)So far stony desertification comprehensive treatment model has been established in both two demonstration plots for engineering treatment and ecological treatment. Through slope-to-terrace method, building reservoirs,farm track and runoff basins, prevent water and soil loss and protect the soil. Ecological management proceeds by the way of forest conservation and national natural forest reserve. In Qingzhen demonstration plot, plant a blockbuster of nursery garden growing green stuff, etc to recover ecosystem by different land utilities. After ecological management, the nutritive element contents in soil are higher which shows that the soil erosion is reducing and soil fertility is increasing. Especially the cultivation of “Dingtan pepper model” and “dragon fruit planting base” in Huajiang demonstration plot with severe soil loss has achieved good ecological effects.(3)(1)Content of CO2 in microbial biomass of Qingzhe demonstration plot is the highest, notably higher than Guanling-Zhenfeng Huajiang demonstration plot because there are much more arable lands of land utilization type in Qingzhen Hongfeng lake demonstration plot. There are more fertilizing amount of nitrogen and phosphorus because the fertilizing of organic fertilizers improves soil microorganism carbon and nitrogen contents in the soil.(2)CO2 concentration in arable land and soil basic respiration is higher than other land-use types. CO2 content is lower in bushwood and grass land. It means that systematical level is lower and easily influenced by human intervention.(3)Through correlation analysis on soil basic respiration, soil microorganism CO2 and soil chemical property, we reach the conclusion: Nitrogen dioxide in the soil influences the activity of soil microorganism and then influences soil basic respiration. Soil respiratory rate is mainly influenced by soil temperature. Solar radiation impacts soil temperature and then influences soil respiration.