旱地不同膜覆盖种植模式对土壤微生物数量的影响

Effects of Plastic Film Mulching on Population of Soil Microbes in Dryland

采用稀释平板法和最大或然数法,对旱地常规覆膜、全膜覆盖双垄沟播"一膜用一年"和全膜覆盖双垄沟播"一膜用两年"3种膜覆盖种植模式的土壤微生物数量进行研究。结果表明,3大类群微生物以细菌数量为最多,放线菌次之,真菌最少。除自生固氮菌外,全膜覆盖双垄沟播"一膜用两年"种植模式能够明显增加土壤碳氮磷生理类群微生物数量。不同生理类群土壤微生物数量基本呈现随土层深度的增加而减少的变化趋势。细菌、放线菌和其他生理类群(除自生固氮菌外)微生物数量之间均呈正相关关系。

Using the dilute plate counting method and the most probable number method,populations of soil microbes were investigated in drylands under conventional film mulching,annual mulching covering two ridges,or biennial mulching covering two ridges.Results show that among the three great groups of microbes,bacteria were the highest in population and followed by actinomyces and fungi.The biennial mulching significantly increased the populations of the soil microbial physiological groups,except for azotobacteria.However,the population of the soil microbial physiological groups decreased with the increase in soil depth.Positive relationships were found of bacteria and actinomyces with soil microbial physiological groups（except for azotobacteria）.