粪肥对不同磷水平土壤磷流失潜力的影响

田间试验结果表明,因施肥方式不同,粪肥施用对不同磷水平土壤磷流失潜力的影响也不相同。在施用的粪肥与表土混合的情况下,粪肥对土壤磷流失的增加量随土壤磷水平的提高而升高。但当粪肥表施不与土壤混合时,情况有所不同。在粪肥表施初期,无论是高磷土壤还是低磷土壤,地表径流中磷浓度都达到较高水平,施肥引起的土壤磷流失的增加量以低磷土壤更为明显。但粪肥表施较长时间后,粪肥对土壤磷流失的增加量也随土壤磷水平的提高而升高。总的来说,控制地表径流磷流失的效果是粪肥与土混施优于表施,流域内粪肥处置应优先施于土壤磷水平较低的土壤中。

Effects of Organic Manure Application on P Runoff from Soils with Different P Levels

The effects of organic maunre application on P runoff from soils on different P levels varied with application methods.The elevated amounts of soil P runoff induced by organic manure application increased with increasing soil P level when organic manure was mixed with surface soils.The effects were different when the organic manure was applied on the field without mixed with soils.In the latter case,P concentration in the initial runoff water was very high for all soils,and the elevated amounts of soil P runoff from organic manure application were more significant in low P soils than those in high P soils.However,P concentration in the runoff water collected four months later after the application decreased significantly,and the elevated amounts of soil P runoff from organic manure application increased with increasing soil P level.The results suggested that mixture application of organic manure with soils was more efficient for controlling P runoff loss than direct surface application,and organic manure should be preferentially applied to lower P soils.