Abstract: To illustrate the short-term changes in soil microbe alteration of fertilizer nutrient input might bring about,samples of red paddy soil were collected from a paddy field under long-term combined application of organic manure and inorganic fertilizer.They were used in an indoor incubation experiment to observe effects of addition of different nutrient elements on soil microbial biomass carbon and functional diversity of BIOLOG communities.Results show that addition of inorganic nutrients lowered microbial biomass carbon by 15%-22% within a short period of time (185 days) and average well color development(D _av)by 55.6%,while addition of organic nutrients raised microbial biomass carbon by 8%-42% and D _av by  992%.In Z(no addition of nutrients)D _av  was increased by 501% within a short period of time,and evenness of microbial community was somewhat lowered,but microbial biomass carbon was not much affected.Besides,addition of different nutrient elements also altered the carbon metabolism pattern of the soil microbial community.Amendment of different nutrient elements into the soil under long-term combined application of organic manure and chemical fertilizer changed significantly ecological features of the soil microbe,which may be embodied in changes in microbial biomass carbon and microbial carbon utilization pattern.

Key words: addition of different nutrient element, soil microbial biomass carbon, microbial carbon utilization pattern