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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。
Wheat pot experiments were conducted from September to October in 2014, and conventional nitrogen fertilizer (CK), nitrogen fertilizer (G), nitrogen fertilizer added glucose and Bacillus megaterium (GY), nitrogen fertilizer added straw (S) Straw and Bacillus megaterium (SY). The changes of greenhouse gas emissions, soil carbon and nitrogen environment and microbial flora were observed to study the effect of different carbon sources and Bacillus megaterium on soil greenhouse gas emissions and microbial influences. The results showed that: (1) Under the conditions of nitrogen application, the addition of glucose (G) and glucose and the treatment of giant Bacillus (GY) had no significant effect on the change of soil microbial carbon content, but decreased the observed species number and species diversity in soil; Inhibited the increase of nitrate nitrogen and ammonium nitrogen, and then inhibited the increase of N 2 O emission, at the same time, promoted the uptake of CH 4 by dry land. (2) If straw was used instead of glucose, straw (S) was applied at the same time of nitrogen application, which significantly reduced soil nitrate nitrogen content in wheat seedling stage, but had no significant effect on N 2 O emission. Compared with straw, glucose can rapidly provide organic carbon, which can better reflect the effect of Bacillus megaterium on improving soil microbial flora and reducing nitrate nitrogen production and N 2 O gas emission as a carbon source.