【摘要】 降水是土壤侵蚀和养分流失的主要驱动力.本文利用野外模拟人工降雨试验,研究不同土地利用类型下水土流失和养分流失.结果表明:林地蓄水保土效果显著,初始产流时间在25m in左右,土壤侵蚀速率仅为裸地的8%.累积径流量和产沙量均与时间呈线性增加,关系为Y=aX-b,径流系数a表现为:裸地>撂荒地>草地>林地.径流和泥沙的迁移导致土壤肥力下降;泥沙结合态是养分流失的主要途径,其养分含量显著高于径流中养分浓度.与裸地的碳、氮和磷养分流失总量相比,撂荒地分别占47.9%、60.8%和46.1%,草地占22.5%、14.4%和17.4%,林地占1.4%、2.8%和2.6%.林地和草地水土保持效果显著,能有效减少养分流失,控制面源污染.更多还原

【Abstract】 Rainfall is the main driving force of soil erosion and nutrient lost,may caused the soil become less fertile,sand deposited in rivers and lakes,water pollution,et al.This article researched on soil erosion and nutrient lost of four different land-use patterns which including naked land,abandoned land,grass land and wood land,with a simulated rainfall equipment.The results showed as follow:(1)there was a significant effect on water and soil conservation of wood land,soil erosion rate was only 8% of naked land,initial runoff-yielding time were about 25min latere after the rainfall began.(2)A linear correlation betwen accumulated amounts of runoff and sediment yield were Y=aX-b,the order of soil erosion rate were naked land>abandoned land>grass land>wood land.(3)The nutrient in sediment was significantly higher than that in run-off,which was the main ways of nutrient losses.Compared with naked land,the percentage of total dissolved organic carbon,total nitrogen and phosphorus lost were of 47.9%,60.8% and 46.1% in abandoned land,22.5%,14.4% and 17.4% in grass land,1.4%,2.8% and 2.6% in wood land,respectively.Both grass land and wood land shows a significant effect on soil and water conservation,which could reduce the nutrient lost and control non-point source pollution,effectivly.更多还原