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为明确秸秆还田的烟田土壤微生态效应,通过3年定位试验研究了不同用量小麦及玉米秸秆还田对植烟土壤酶活性及细菌群落多样性的影响。结果表明,秸秆还田可不同程度提高土壤蔗糖酶、碱性磷酸酶及脲酶活性。玉米秸秆还田的土壤蔗糖酶和碱性磷酸酶活性高于等量小麦秸秆还田处理。与对照相比,玉米及小麦秸秆中低量(4500及1500 kg/hm~2)还田后土壤的细菌群落多样性下降,而高量(7500 kg/hm~2)还田后则不变或稍有增加。此外,高量玉米秸秆还田与其他处理间的土壤细菌群落相似系数仅为0.57,表明其群落结构变化较大。而且低、中、高量玉米秸秆还田土壤DGGE图谱中的特异条带分别属于乳酸球菌(Lactococcus)、不可培养细菌(Uncultured bacterium)及硝化螺菌(Nitrospira)。可见,两种秸秆还田均能提高植烟土壤的蔗糖酶、碱性磷酸酶和脲酶活性,且玉米秸秆在高量还田后可增加土壤细菌群落的丰度及多样性。
In order to clarify the soil microbial ecological effects of returning straw to soil, the effects of wheat and corn stalks returning to the field on soil enzyme activities and bacterial community diversity were studied through three-year experiment. The results showed that straw returning to varying degrees could improve the activity of soil sucrase, alkaline phosphatase and urease. The activity of soil invertase and alkaline phosphatase of corn stalks was higher than that of wheat straw returning to the same field. Compared with the control, the bacterial community diversity of low soil (4500 and 1500 kg / hm ~ 2) in maize and wheat straw decreased, while that of high soil fertility (7500 kg / hm ~ 2) Or slightly increased. In addition, the similarity coefficient of soil bacterial community between the high amount of corn stalks and other treatments was only 0.57, indicating that the community structure changed greatly. Moreover, the specific bands in the DGGE profiles of soil with low, medium and high levels of corn stover were belong to Lactococcus, Uncultured bacterium and Nitrospira, respectively. It can be seen that both straw returning and fielding can increase the sucrase, alkaline phosphatase and urease activities of tobacco planting soil, and the corn stalk can increase the abundance and diversity of soil bacterial community after returning high amount of soil.