短語詞組短語soil biological degradation 土壤生物退化soil fertility degradation 土壤肥力退化soil erosion degradation 土壤侵蝕退化soil quality degradation 土壤質(zhì)量惡化soil pollution degradation 土壤汙染退化soil structure degradation 土壤結(jié)搆退化soil physical degradation 土壤物理性質(zhì)退化soil quality degradation index 土壤質(zhì)量退化指數(shù)red soil eroded degradation land 紅壤侵蝕退化地 返回 soil degradation