川南地区不同退耕地对土壤抗蚀性的影响

对川南坡地退耕5年后的慈竹林地、杂交竹林地、桤木+慈竹混交林地和弃耕地土壤抗蚀性变化进行了研究,探讨了土壤抗蚀性指标间的关系。结果表明:退耕后土壤水稳性团聚体平均质量直径、结构性颗粒指数、团聚状况、团聚度、物理稳定性指数和有机质增加,土壤结构体破坏率、不稳定团粒指数、分散率、侵蚀系数和受蚀性指数降低;各退耕地土壤抗蚀性综合主成分值为-4.466~3.436,呈现出慈竹林地杂交竹林地桤木+慈竹混交林地弃耕地对照的特点;土壤有机质与大多数抗蚀性指标具有显著相关性,且与抗蚀性综合主成分值呈极显著正相关,说明坡地退耕后土壤有机质增加是土壤抗蚀性增强的关键,坡地退耕成慈竹林地更有利于增强研究区土壤抗蚀性。

Influence of Different Abandoned Lands to Corrosion Resistance of Soil in South Sichuan

The paper studies the variations of corrosion resistance of soil of Neosinocalamus affinis stand,hybrid bamboo stand,Alnus cremastogyne+Neosinocalamus affinis stand of abandoned cultivating sloped land for 5 years and abandoned farmland in the south of Sichuan and discusses the relationships between corrosion resistance indexes of soil.The outcomes show that a) the mean weight diameter of soil water stable aggregate,structural grain index,aggregation status,degree of aggregation,physical stability index and organic matter increase and the ped destructive rate,unstable aggregate index,dispersion rate,erosion coefficient and eroded index decrease after abandoned cultivation;b) the principal component values of corrosion resistance of soil of each abandoned cultivating land is from-4.466 to 3.436,showing the characteristics of Neosinocalamus affinis stand >hybrid bamboo stand>Alnus cremastogyne+Neosinocalamus affinis stand>abandoned farmland >checked land;c) soil organic matter has obvious relativity with most resistance index and significant positive correlation with the principal component values of corrosion resistance,showing the increase of soil organic matter after abandoned cultivation is the key for increasing the corrosion resistance of soil and conversion of cropland to Neosinocalamus affinis stand is advantageous for increasing corrosion resistance of soil in the studied region.