The Lippia Nodiflora(L.)Greene Soil Improvement Effect Research In The Karst Area

This paper studies rely on the national "eleven five" technology support program (2006BAC01A16) and the National Bureau of the 948 project done in research.Chongqing city Beibei District of Zhong Liang mountain as a study area, collecting 1-year Lippia nodiflora(L.)Greene,2-year of economic forest, a perennial natural shrub-grass piece, two pieces of 15-year and 20-year artificial forests, a piece of farmland and 30-year of secondary forest, as study of different land use types, comparative analysis of the Lippia nodiflora(L) Greene in soil fertility improvement effect.In addition, also selected represent 25 degrees,25 degrees to 15 degrees,15 degrees, as well as close to the ground,the four representative slope plant the Lippia nodiflora(L.)Greene, as research,under different slope gradients in Lippia nodiflora(L.)Greene fertility maintaining effects of study object.Through collecting the relevant papers about karst, researching present situation soil fertility, improved method and the Lippia nodiflora(L.)Greene in karst.And using Excel and SPSS 17 software for data analysis and processing.By hydrometer method for the determination of soil particle composition, potassium dichromate method for the determination of organic matter, perchloric acid-sulfuric acid solution-Determination of total nitrogen, perchloric acid and acid leaching molybdenum antimony resistance to colorimetric spectrophotometric method for the determination of total phosphorus, perchloric acid and sulphuric acid-Flame photometric method for the determination of total potassium, diffusion absorption method for the determination of nitrogen, sodium hydrogen carbonate-spectrophotometry for determination of available phosphorus, flame photometric method for the determination of potassium to studing of different vegetation types on soil physical and chemical properties in karst, comparing the different slope cases, the same Lippia nodiflora(L.)Greene slope of the soil physical and chemical properties.To search for the Lippia nodiflora(L.)Greene soil amelioration effects and under different slope gradients, Lippia nodiflora(L.)Greene soil fertility condition, enhances the Lippia nodiflora(L.)Greene in karst mountain researching situation about.The experimental results show that, under different vegetation on soil improvement effects, Lippia nodiflora(L.)Greene has a certain improvement effect. Lippia nodiflora(L.)Greene soil structure better than the cultivated, the 15-year and 2-year of artificial forest land reasonable. The surface soil desertification is decreased by 30%, the 0.001mm clay content increased by 25%. Compared with other natural land use types, Lippia nodiflora(L.)Greene demonstrated its superiority, the 0.05mm sand particles and the 0.001mm clay ratio and natural forest land type corresponding to a considerable proportion, and significantly less than other artificial land types soil particle corresponding to particles. The water content of 21.36%, second only to the perennial natural shrub-grass and 15-year of artificial forest. The pH low, and the content of organic matter high show that Lippia nodiflora(L.)Greene in a short period of time to rich humus layer, reduce the soil pH, Improve soil nutrient. The Lippia nodiflora(L.)Greene could significantly increase soil nutrients in which the total nitrogen, available phosphorus, and total phosphorus content was higher, respectively, 19.71g/kg,31.86mg/kg and 2.98g/kg. Higher than other vegetation types several times to several times, organic matter,total nitrogen and total phosphorus with high consistency.And in contrast to its original land type farmland, soil texture, moisture, organic matter, and other nutrients are increased. The Lippia nodiflora(L.)Greene can indeed on the soil improvement, improve soil nutrients and soil texture, but also, the improved effect is better than that of cultivated land and planting time shorter planted woodland.The physicochemical properties of soils with Lippia nodiflora(L.)Greene in different slope have wave motion, but no obvious with increasing slope and nutrients in the soil erosion condition. The known number of research into Lippia nodiflora(L.)Greene show that on slope has obvious solid fertilizer and fertilizer effect, soil moisture, organic matter, total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium had lost just a little.The Lippia nodiflora(L.)Greene on the slope has keep the slope soil and maintain soil fertility.The Lippia nodiflora(L.)Greene can form a large number of aboveground and underground biomass. Grass roots on soil erosion has reduced the role of grass roots, rock and soil organic matter of death, and the live roots secrete substances can be used as a soil particle aggregates of cementing agent, with roots, interspersed with coiled, tangles, can promote the formation of large aggregates in soil. It is not only beneficial to soil erosion, but also conducive to the soil of clay, organic matter and other nutrients save.