绿肥翻压还土的生态效应及其对土壤主要物理性状的影响

针对湘西旱地干旱贫瘠的特点，采用田间小区试验，以不同绿肥为试验作物，对湘西旱地植烟土壤种植绿肥翻压还土的生态效应及土壤主要物理性状的影响进行研究。结果表明，旱地土壤填闲种植绿肥翻压还土，可以促进大气—作物—土壤生态系统的物质和能量循环，固定大气中的碳和氮，活化和富集土壤养分，增加土壤有机碳和养分物质的投入，提高土壤养分有效性。增加土壤有机质，提高幅度为3.2%~9.5%。降低土壤容重；pH最高降低0.23个单位。而土壤的孔隙度、阳离子交换量和持水能力等都有较大幅度提高，最大提高幅度分别为6.4%、21.6%和3.4%。绿肥翻压还土具有良好的培肥改土和生态效应，改善土壤的物理性状。

Effect of Ploughed-back Green Manures on Soil Physical Properties and Its Corresponding Ecological Benefit

The objective of this paper was to investigate the effect of ploughed-back green manures on soil physical characters and its corresponding ecological effect by field plot experiment in tobacco-planting dryland soil in west of Hunan Province, as the dryland soil is drought and poor. The results showed that, ploughed-back green manures could improve cycling of material and energy in atmosphere-plant-soil ecological system, fixation of carbon and nitrogen from atmosphere, soil nutrient activation and enrichment, increase soil organic carbon and nutrient input and improve the soil nutrient efficiency, increase soil organic matter, increased by 3.2%-9.5%. Reduce the soil bulk density, the highest pH was lower 0.23 units. In addition, soil physical properties also could be enhanced obviously soil porosity, CEC, water-holding capacity. The largest increase was 6.4%, 21.6% and 3.4% respectively. Therefore, ploughed-back green manures had favorable effect with soil fertilization and ecology, and it could improve soil physical properties.