Effects of swine manure application on p losses from different farmlands under simulated rainfall in dianchi watershed of Yunnan province

Field in-situ trials were carried out to study the effects of swine manure application on phosphorous losses from different farmlands under rainfall simulation in Dianchi watershed of Yunnan province. The results show that with the increase of applying swine manure amounts, concentrations of various phosphorus forms in runoff water from farmland are increased. The average concentrations of run off phosphorus are highly correlated (correlation coefficients 0.9) with the manure application rates. Particulate phosphorus is the main form in runoff water. Particulate phosphorus is also the main form in leaching water when the manure application rate is low, while dissolved phosphorus is the main form in leaching water when the manure rate is from middle to high. Under the same level of swine manure application, concentrations of various phosphorus forms in runoff water from different farmlands have the same trend: vegetable field flower field cropland.