The Character Of Nitrogen And Phosphorus Migration And Influence Factor In Karst Area

The nitrogen and phosphorus migration characteristic and influence factor in Karst area were studied through sample analyze to representative karst nonirrigated farmland and the experiment of pot, in Karst area. the main result of study is as follows:1. Through sample to analyze to representative lime soil, the result shows: Karst nonirrigated farmland soil the obvious difference appears in the phosphorus and nitrogen of content under the different soil terms, alkali its solve nitrogen size order of content the vegetables ground >Maize ground >Cigarette ground >Maize soybean intercropping ground; The size order of the effective phosphorus content is the vegetables ground >Cigarette ground >Maize ground >Maize soybean intercropping ground.2. The concentration of NH₄⁺,NO₃^-,PO₄^3- in the surface runoff in Karst area have difference significantly under various land use. The size order of the content of NH₄⁺,NO₃^- is the vegetables ground >Maize ground >Cigarette ground> maize soybean intercropping ground; The size order of the content of PO₄^3-is the vegetables ground >Cigarette ground >Maize ground>Maize soybean intercropping ground.3. The content of NO3" and effective nitrogen of soil have obvious positive correlation in the surface runoff of hill area on land of karst (r is 0.912), the content of NH₄⁺ and content of effective nitrogen of soil have obvious positive correlation in the surface flow(r is 0.947), the content of PO₄^3- and effective phosphorus of soil have obvious positive correlation in the surface flow(r is 0.962).4. NH₄⁺,NO₃^-,PO₄^3- migration law were influenced by growth course of crop (maize , water celery , root grasses , poplars , grasses ) in Karst...