大气CO_2与吡虫啉对甘蓝土壤细菌与微生物生物量C的影响

Effect of elevated CO_2 concentration and imidacloprid on culturable bacteria and microbial biomass carbon in cabbage(Brassica oleracea L. var. capitata)soil

采用田间开顶式CO2控制气室(OTC),研究了375μL/L、750μL/L两个CO2浓度和CK、LC50、LC903种吡虫啉浓度处理条件下,甘蓝根际土壤细菌与非根际土壤微生物生物量C的变化。750μL/L CO2处理对甘蓝根际细菌数量显著增加(P<0.01),而在同一CO2水平下各农药处理间并无显著差异;根区土壤微生物生物量C只有在750μL/L CO2且无吡虫啉处理的条件下显著(P<0.05)下降,在LC50、LC90处理的影响下并不显著。同一CO2水平下,根区土壤微生物生物量C受农药处理的影响不明显。

Responses of bacteria in the presence rhizosphere soil and soil microbial biomass carbon in non-rhizosphere cabbage to elevated CO2 and three concentrations of imidacloprid were examined in the open-top chambers（OTC）.Numbers of bacteria in rhizosphere soil increased significantly（P0.01） with elevated CO2 but imidacloprid had no effect on bacteria.Microbial biomass carbon was lower in non-rhizosphere of cabbage under elevated CO2 than ambient CO2 concentrations when imidacloprid was not applied.Regardless of CO2 levels,imidacloprid affects were not significant for the numbers of bacteria in rhizosphere soil.