长期施肥对土壤溶磷微生物的影响

Effect of Long-Term Fertilization on Phosphate-Solubilizing Microorganisms

在室内条件下研究了施肥措施对土壤微生物总量、溶磷细菌、土壤有机碳的影响,同时比较了溶磷细菌与有机碳、有效磷、微生物C和硝态氮的相关性。七年的结果表明,NPK、NPK+绿肥促进土壤微生物总量增长,磷肥过量施用对微生物有抑制作用。溶磷细菌对施肥措施非常敏感,化肥和绿肥施用导致溶磷细菌急剧减少;溶磷细菌数量与土壤有效磷含量成负相关。为保持土壤微生物群体和增加溶磷细菌数量,应避免过量施用磷肥。油菜翻压后产生的某些物质可能对土壤溶磷细菌有杀死或抑制作用。

The effect of long-term fertilization on soil microflora, number of inorganic phosphate solubilizing bacteria and organic carbon were studied. The relationship between phosphate-solubilizing bacteria, organic C, microbial biomass and available N, P were also studied. NPK and NPK plus green manure significantly increased the total number of microorganisms, but decreased P solubilizing bacteria. There was a negative relation between the number of phosphate-solubilizing bacteria and soil available P. This study showed that excessive application of inorganic phosphate was a serious problem of inhibiting the growth of soil microflora and phosphate-solubilizing bacteria. Canola may produce some toxic substances which destroy or inhibit phosphate solubilizing bacteria.