免耕对土壤微生物生理类群的群落结构与生态特征的影响

目的]研究免耕对土壤微生物生理类群的群落结构与生态特征的影响。方法]用＂S＂形取样法分别采取0～5、5～10、10～30cm土样,用不同培养基培养各种细菌。用平板法测定自生固氮细菌、有机磷细菌、无机磷细菌、纤维素分解细菌和硅酸盐细菌含量;用稀释法测定氨化细菌、硝化细菌含量。最后计算出群落生态指标H和Ea。结果]免耕对土壤微生物生理类群的结构组成有一定影响,土壤微生物各生理类群的数量呈现随土层深度的加深而减少的变化趋势;免耕处理下土壤微生物生理类群的多样性与均匀度在0～5和5～10cm土层均明显高于翻耕处理的土层。结论]免耕可有效地为当季作物提供养分。

Effect of Non-tillage on the Structure of the Microbial Community of Physiological Group in Soil and its Ecological Characteristics

Objective]The impact of non-tillage on the structure of microbial community of physiological group in soil and its ecological characteristics was studied. Method]The soil sample was taken at the depth of 0～5 cm,5～10 cm and 10～30 cm section in field with the method of "S"-shaped sampling and the samples were cultured with a variety of bacterial medium. The content of the bacteria of self-nitrogen-fixing,organic phosphorus,inorganic phosphorus,cellulose-decomposing and silicate bacteria was tested with the Plate Method and the content of ammonification and nitrifying bacteria was tested with the Dilution Method. And finally,the indicator of ecological community H and Ea was calculated. Results]The results showed that non-tillage had some influence on the composition in the microbial structure of physiological group in soil. The microbial population of the various physiological groups in soil was reduced with the depth-increasing of the soil section. soil dealing with The diversity and uniformity of the physiological group of the microbial community in the depth of 0～5 cm and 5～10 cm section in soil under the condition of non-tillage were significantly higher than these under the condition of tillage treatment. Conclusion]The treatment of non-tillage could effectively release the nutrients for seasonal crops.