Effect of bacterivorous nematode on soil microbial biomass and microbiocoen-(osis)
食细菌线虫对土壤微生物量和微生物群落结构的影响

Researches on the interaction between nematodes and microbes were usually carried out in gnotobiotic microcosm, in order to know the interaction in open soil system, we inoculated bacterivorous nematode (Protorhabditis sp) into the open soil system with and without wheat to study the effects of bacterivorous nematodes and their interactions with roots on soil microbial biomass and microriocoenosis at different growth stages of wheat. The results indicated that, the inoculation of bacterivorous nematodes increased the content of SMBC, SMBN and SMBP by 26.4%, 32.9% and 21.8% respectively, and the difference were obviously in most treatments except some treatments of bulk soil and soil without plant. The content of SMBC, SMBN and SMBP in rhizosphere soil were much more than that in the bulk soil and soil without plant. The influence of nematode inoculation on SMBC, SMBN and SMBP was in the sequence of SMBN> SMBC> SMBP, and the influence of nematode inoculation on SMBC was most obvious in rhizosphere soil. The inoculation of bacterivorous nematodes had significant effects on bacteria, fungi and actinomycetes number. The bacteria number significantly increased in treatments with nematodes except in rhizosphere soil at seedling stage of wheat. The influence of nematode inoculation on fungi and actinomycetes number was bigger than on bacteria number, the fungi and actinomycetes number were increased by 48.5% and 68.2% respectively. There was no significant correlation between bacteria number and SMBC content in all treatments, while there were significant correlation between fungi number and SMBC content in rhizosphere soil and bulk soil and significant correlation between actinomycetes number and SMBC content in soil without plant.