Abstract

The purpose of this study was to examine the influence of sewage irrigation on the quantity and distribution of soil microorganisms, and to explore the relationship between the content of soil nutrients and the quantity of different microorganism. The results showed that the quantities of the soil actinomycetes, fungi, nitrite oxidizing bacteria (NOB), nitrate bacteria (NB) and denitrifying bacteria (DB) were reduced, while those of soil bacteria, ammonia oxidizing bacteria (AOB) and aerobic cellulose decomposing bacteria (CDB) were increased after sewage irrigation. The distribution of fungi, azotobacter (AB) and cellulose decomposing bacteria (CDB) in the soil rhizosphere of soybean, corn and rice were significantly altered after sewage irrigation. The quantity of soil microorganism in the soil after sewage irrigations was significantly correlated with the soil content of organic substance, ammonia nitrogen and available phosphorous. These results provided theoretical basis for the application and standard establishment of sewage irrigation in the farmland.

Key words: Sewage irrigation, soil microorganisms, soil nutrient, Kuihe River, farmland.