Characteristics Of The Nitrogen And Phosphorus Loss In The Runoff Under Different Soil And Water Conservation Measures On The Slope Orchard

Because of climate and people’s unreasonable activities, the red slope orchard has a serious problem about the soil and water loss. Nitrogen and phosphorus from the process of soil and water loss have become a main source of water eutrophication. In this thesis, with the method of observing the runoff plots, we analyzed the loss characteristics of runoff and N,P in different plots under five different treatment measures in the red slope orchard including:cleaning tillage, strip covering, whole covering, level bench terrace(cleaning tillage), level bench terrace(interplant). Meanwhile, the effects of precipitation rainfall capacity and the volume of runoff on the loss characteristics were studied. The main results obtained in this study are as follows:(1) During20011-2012, the annual rainfalls were948mm and1335.6mm and the rainfall was mainly concentrated from May to November.(2) The volume of runoff in strip covering and whole covering took up only17%and19%when compared with cleaning tillage and level bench terrace(interplant) is53.79%to level bench terrace(cleaning tillage). The volume of runoff in level bench terrace (cleaning tillage) is less than cleaning tillage. It meant biological measure and engineering measure could control the loss effectively.(3) The TN concentration in the runoff in cleaning tillage was the highest among these measures. But there are many differences between NH4+-N and NO3-N concentration in different measures. NO3-N concentration was larger than NH4+-N in all measures. Different kinds of nitrogen had a higher concentration from April to June; The amount of different kinds of nitrogen was:cleaning tillage>level bench terrace (cleaning tillage)> whole covering> strip covering> level bench terrace (interplant).It usually showed a linear function relationship between Various forms of nitrogen loss and rainfall and Various forms of nitrogen loss and runoff (y=ax+b), but the a net in cleaning tillage was the largest.(4) The TP in the runoff in whole covering was the lowest among these measures while it was higher in cleaning tillage and level bench terrace (cleaning tillage). The TP concentration in the runoff was higher in May. The amount of TP loss always had a linear function relationship with rainfall(y=ax+b).