坡地土壤侵蚀与养分流失过程的研究

Studies on the Process of Soil Erosion and Nutrient Loss in the Sloping Lands

本文采用人工降雨室内试验,研究了坡地土壤侵蚀与有机质、全氮和有效磷养分的流失过程。坡度、雨强对其流失过程的影响;比较分析了裸露坡地及沙网覆盖两种处理的土壤侵蚀与养分流失过程。结果表明:随坡度,雨强增大,养分流失量也增加;试验小区覆盖纱网消除雨滴动能后,土壤养分流失量比裸露坡地减少60%左右;养分流失量与土壤流失量呈正相关,多数泥沙样中有效养分的含量高于土壤中养分含量,尤以有效磷更为显著。

This paper studied the process of soil erosion and nutrientl oss including organicmatter, total N and available P in the sloping lands through the lab artific ial rainfall, a-nd the effects of slope gradient and rainfall intensity upon the lossing process. It also analysed the process of soil erosion and nutrient loss of two treatemnts in the bare sloping lands and the net covering sloping lands. The results indica ted that the amount of nutrient loss went up with an increase in slope gradients and rainfallintensity, and that after the kinetic energy of raindrop was eliminated by the covering net in the experimental plot, the amount of soil and nutrient loss was reduced by 60% or so as compared to that in the bare sloping lands. The amount of nutrient loss was in the correlation with soil loss. The available nutrients in most of sediment sampes were higher than those in the soil with available P in particular.