碳源和巨大芽孢杆菌添加对土壤微生物环境及N_2O、CH_4排放的影响

2014年9-10月设计小麦盆栽试验,设置常规施氮处理(CK)、氮肥添加葡萄糖(G)、氮肥添加葡萄糖和巨大芽孢杆菌(Bacillus megaterium,GY)、氮肥添加秸秆(S)、氮肥添加秸秆和巨大芽孢杆菌(SY)5种处理,通过观测小麦苗期温室气体排放、土壤碳氮环境以及微生物菌群等变化,以分析研究不同碳源和巨大芽孢杆菌对土壤温室气体排放和微生物的影响。结果表明:(1)在施氮的同时增施葡萄糖(G)以及葡萄糖和巨大芽孢杆菌处理(GY),对土壤微生物碳含量变化影响不显著,但降低土壤观测物种数与物种多样性;明显抑制硝态氮和铵态氮的增加,继而抑制N_2O排放量的增加,同时促进了旱地土壤对CH_4的吸收。(2)若用秸秆代替葡萄糖,在施氮的同时增施秸秆(S),显著减少小麦苗期土壤硝态氮含量,但对N_2O排放影响不显著。与秸秆相比,葡萄糖能快速提供有机碳,作为碳源更能体现巨大芽孢杆菌改善土壤微生物菌群、减少硝态氮生成及N_2O气体排放的效果。

Effects of Carbon Source andBacillus megaterium on Soil Microbial Environment and N2O,CH4Emission

The potted wheat experiment was conducted in September-October 2014, five treatments were set up as follows: regular nitrogen treatment(CK) nitrogen added with glucose (G), nitrogen added with glucose andBacillus megaterium (GY), nitrogen added with straw(S), nitrogen added with straw andBacillus megaterium(SY). Based on monitoring the changes of greenhouse gas emissions, soil carbon and nitrogen environment and microbial flora at seedling stage of wheat, the impacts on greenhouse gas emissions and soil microorganisms for different carbon sources andBacillus megaterium were analyzed. The results showed:(1)there was no significant effect on carbon changes of soil microbial, but the soil microbial species and species diversity decreased with treatment of nitrogen added with glucose(G) and glucose andBacillus megaterium (GY); While the N2O emissions was inhibited as the nitrate nitrogen and ammonium nitrogen were obviously inhibited in addition, the CH4 absorption of upland soil was promoted.(2)The nitrate nitrogen reduced significantly while the changes of N2O emissions was not obvious with treatment of nitrogen added with straw(S) at seeding stage of wheat. So the glucose which could provide organic carbon quickly was better than straw as carbon source to reflect the influence of that the huge bacillus could improve soil microbial flora, reduce the nitrate nitrogen generation and N2O emissions.