soilbag土工袋soiln.土地；土壤；污物，粪便v.弄污soil and water erosion水土流失soil reclamation plant土壤改良植物soil forming processes土壤形成过程soil erosion intensity土壤侵蚀强度Soil moisture in field农田墒情Soil coveringthickness覆土厚度Soil layer strainmeter土层应变仪soil nutrient diagnose土壤营养诊断soil enrichment method土壤加富法Soil nitrogen transfer土壤氮素转化