云南元谋干热河谷区土壤侵蚀对土壤肥力的影响

探讨了云南元谋干热河谷区土壤侵蚀对土壤肥力性质的影响．研究表明，土壤侵蚀使土壤中全氮、全磷、全钾以及碱解氮、速效磷、速效钾等养分淋失；同时，有机质含量减少，土壤有机无机复合量降低，松结态腐殖质减少．Ａ／Ｃ值下降；土壤中的过氧化氢酶、蔗糖酶、脲酶等活性也因侵蚀而降低．土壤侵蚀越强烈，土壤肥力退化愈严重．

Effects of Soil Erosion on Soil Fertility in Yuanmou Dry and Hot Valley, Yunnan

The influences of soil erosion on soil fertility properties in Yuanmou dry and hot valley, Yunnan,have been discussed. Results showed that, in the eroded sods, the contents of the total nitrogen,total phosphorus, total potassium, alkali-hydrolyzable nitrogen, available phosphorus and available potassium decreased, the organic matter reduced, the contents of the orsano-mineral complex and loosely combined humus decreased, and the A/C ratiO lowered. Moreover, the activity of the catalase, sucroase and urease in the eroded soils decreased. The more severely the sods were eroded, the more seriously the soil fertility degraded.