四川盆地紫色土小流域土壤的可蚀性

摘要

In order to reveal the impacts of different patterns of land use and vegetation types on the purple soil erodibility,investigated and monitored the soil properties of surface soil（0-20cm） in forestry land,garden-plot and cultivated land of 3 typical agro-watersheds in purple soil region,and the values of soil erodibility K were calculated by using the EPIC model.Results show that the order of the K is SP4SP7SP5SP2SP6SP3SP1.the K value is lowly correlated with the total phosphorus,while others are significant,and even extremely significant.The correlation of K values and impact-factors is TOCSANSIL=CLA TNTP.Thus,the principal countermeasures to improve soil anti-erodibility for the purple soil are to improve the organic matter,reduce the quantity of chemical fertilizer,promote soil-aggregate formation,and increase aggregate ratio.%为揭示不同土地利用方式和植被类型对紫色土壤可蚀性的影响,调查和测试了紫色土丘陵区3个典型小流域内林地、园地和旱耕地的表层土壤（0-20 cm）的理化性质,并利用EPIC公式计算了土壤可蚀性K值,结果表明：样地表层土壤（0-20 cm）可蚀性K值大小顺序依次是：SP4〉SP7〉SP5〉SP2〉SP6〉SP3〉SP1;除全磷与K值相关性较小外,K值与其他影响因子达到了显著（极显著）相关;K值与各影响因子之间的相关程度：有机碳〉砂粒〉粉粒=黏粒〉全氮〉全磷。因此,提高有机碳含量,降低化肥的使用量,促进土壤团聚体形成,增加团聚度,是增加紫色土抗蚀性能的重要途径。