The Spatial Pattern And Influencers Of Soil Nutrient In Typical Karst Watershed Manage Areas

The drought and the little rain weather in southwest China in2010with its lastedfor a long time, wide influence and big harm, was known as the "once-in-a-lifetime"of drought.The worst hit area of this drought was in karst region of southwest, thisarea with its weak ecological environment, poverty population, traffic inconvenienceand poor soil quality that are familiar to us. The coming of this drought make thepeople of this area were more difficult and miserable in life.Therefore, making the region’s ecological research in this area has the importantpractical significance for the local people’s production and life.This paper uses thekarst area in Tiandeng Tuanle and DouAn Chengjiang small watershed as an example,paper studies the soil as the research center,and studies the change of soil nutrientindex as the research object.The soil is very important factor for the plant growth andagricultural production. The quality of the soil nutrient has direct impact on the speedof the plants growth and the high-low harvest of the crop, and it is directly related tothe local residents’ production and life of the karst area. This paper mainly research onthe following several aspects.(1) The spatial distribution pattern of soil nutrient in karst small watershed. Iuse the ordinary kriging interpolation method of analysis of GIS and statisticalanalysis to explain the space distribution condition of the moisture content, pHcontent, organic matter content, total nitrogen content, total phosphorus content, totalpotassium content, alkali solution nitrogen content, the rapid available phosphorus content and the rapid available potassium content in Soil nutrient index. And then Iwill find the certain regularity of the changing spatial distribution of the nutrientindex.(2)The analysis of the changing soil nutrient and the influence factors underthe different condition in karst.Contrast to the different time period, the soil nutrienthas improved in researched area than1990. And I found that the order of the changeregularity of the most of the nutrients in these two small watersheds from high to lowis woodland, shrub land, grassland by the variance analysis of soil nutrients underdifferent vegetation and the contrast of the mean value of nutrient according to thesampling of different types of sample point. And it shows that the change of Tuanlesmall watershed is more remarkable than its in chengjiang small watershed by thevariance analysis soil nutrients under different utilization of cultivated land, and theorder of the change regularity of the most of the nutrients in these two smallwatersheds is valley cultivated land, abandoned farmland, slope farmland.(3)The comprehensive analysis of the soil nutrient indexes in the Karst smallwatershed. It shows that the positive correlation of the organic matter and totalnitrogen in the researched area is very significant and the correlation between pHvalue and other soil nutrient index are weak by the comprehensive analysis of thecollection soil nutrient in these two small watershed.From the scoring of principalcomponent, the order of sample points of different types from big to small iswoodland, shrub land, valley cultivated land, grassland, abandoned farmland, slopefarmland.