紫云英和秸秆还田对土壤肥力性状的影响

在湖北省荆州市绿肥长期定位试验的基础上,研究紫云英种植还田(MV)和水稻秸秆还田(S)对水稻土表层(0~20 cm)各形态养分、活性有机碳及氧化铁的影响。结果表明:与对照(CK)处理相比,紫云英还田能有效增加土壤有机质、碱解氮、颗粒有机碳的含量,增幅分别为1.40%~13.11%、0.08%~12.24%、1.01%~12.56%;紫云英单独还田的处理土壤有效磷、速效钾含量较CK处理降低,在施用化肥(NPK)及秸秆还田后明显增加;紫云英还田各处理土壤的非晶质铁、络合铁含量和铁的活化度较CK处理增加(除部分处理外),增幅分别为0.87%~12.30%、7.98%~30.88%、0.31%~11.66%,均表现为S+MV+NPK处理的增幅最大。紫云英、秸秆还田均能有效提高土壤肥力水平,紫云英还田对土壤肥力水平的提升效果好于秸秆还田,两者配合还田效果最好。

Effects of Chinese milk vetch and straw returning on soil fertility characters

Based on long-term green manure experiments in Jingzhou Hubei Province,the composition characteristics of nutrients,active organic carbon and iron oxide in the surface layer(0~20 cm)of paddy soil were studied under the conditions of Chinese milk vetch planting and returning(MV),and rice straw returning(S).The results showed that compared with control(CK)treatment,Chinese milk vetch returning effectively increased the content of soil organic matter,available nitrogen and particulate organic carbon,which increased by 1.40%~13.11%,0.08%~12.24%,1.01%~12.56%,respectively.Soil available phosphorus and potassium contents in Chinese milk vetch returning alone treatment were lower than those of CK,but they increased significantly after applying chemical fertilizer(NPK)and straw returning.Except for some treatments,the contents of amorphous iron,complex iron and the activation degree of iron oxides in different treatments of Chinese milk vetch returning increased significantly compared with CK,with the increase of 0.87%~12.30%,7.98%~30.88%,0.31%~11.66%,respectively,and the largest increase showed in S+MV+NPK treatment.Both Chinese milk vetch and straw returning could effectively improve soil fertility level.The effect of Chinese milk vetch returning on soil fertility was better than that of straw returning.The combination of Chinese milk vetch and straw returning had the best effect.