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为明确硝化抑制剂对覆膜稻田CH_4和N_2O排放的影响,采用静态箱-气相色谱法和荧光定量PCR技术研究了双氰胺(Dicyandiamide,DCD)和2-氯-6-(三氯甲基)吡啶(Nitrapyrin,CP)两种硝化抑制剂的配施(处理为:覆膜施用尿素,PM;覆膜施用尿素配施DCD,PM+DCD;覆膜施用尿素配施CP,PM+CP)对覆膜栽培下稻田CH_4和N_2O排放及其相关功能菌群落丰度的影响。结果表明:整个水稻生长期,配施DCD(PM+DCD)显著降低N_2O季节总排放(P<0.05),降幅达24%,提高CH_4季节总排放(P>0.05);配施CP(PM+CP)同时降低CH_4和N_2O的季节总排放,降幅均为11%。CH_4排放主要集中在水稻分蘖盛期,此阶段,配施DCD显著提高产甲烷菌群落丰度,降低甲烷氧化菌群落丰度(P<0.05),而配施CP则降低产甲烷菌群落丰度,显著提高甲烷氧化菌群落丰度(P<0.05),这可能是由于配施DCD提高了CH_4排放总量而配施CP降低了CH_4排放。在N_2O排放集中时期(水稻生长前期),配施DCD和CP均降低了氨氧化菌群落丰度,显著提高了反硝化菌群落丰度的趋势(P<0.05)。配施DCD(PM+DCD)、配施CP(PM+CP)和覆膜栽培(PM)处理的碳交易成本GWP-cost分别为831、735和822 yuan·hm~(-2);温室气体排放强度GHGI分别为0.69、0.61和0.70 t·t~(-1);产量分别为9.20、9.24和9.00 t·hm~(-2)。因此,综合考虑温室气体效应和经济效益,覆膜栽培稻田模式下,配施CP可以保证增产和减排,值得推广。
In order to clarify the effect of nitrification inhibitors on the emission of CH_4 and N_2O in paddy rice fields, the effects of Dicyandiamide (DCD) and 2-chloro-6- (trichloromethyl ) Were combined with Nitrification inhibitor (Nitrapyrin, CP) for nitrification inhibitors (treatment: coated urea, PM; coated urea applied DCD, PM + DCD; urea coated with CP, PM + CP) Effect of Emission of CH_4 and N_2O and Abundance of Related Function Communities on Rice Paddy Soil with Plastic Mulching. The results showed that PMD + DCD significantly reduced the seasonal total N_2O emission (P <0.05), decreased by 24%, and increased the total CH_4 season discharge (P> 0.05) CP) reduce the seasonal total emissions of CH_4 and N_2O by 11%. CH4 emissions mainly concentrated in the tillering stage of rice. In this stage, the application of DCD significantly increased the abundance of methanogens and decreased the abundance of methanotrophs (P <0.05), whereas the application of CP decreased the abundance of methanogens , Significantly increased the abundance of methane oxidizing bacteria (P <0.05). This may be attributed to the reduction of CH 4 emission by the combination of CP with DCD to increase the total CH 4 emissions. During the concentrated period of N 2 O emission (early stage of rice growth), the application of DCD and CP both decreased the abundance of ammonia oxidizing bacteria and significantly increased the abundance of denitrifying bacteria (P <0.05). GWP-cost of carbon transaction costs of DCD (PM + DCD), CP (PM + CP) and film mulching (PM) treatment were 831,735 and 822 yuan · hm -2, respectively. The emission intensity of GHGI was 0.69,0.61 and 0.70 t · t -1, respectively. The yield of the two crops were 9.20,9.24 and 9.00 t · hm -2, respectively. Therefore, taking greenhouse gas effect and economic benefits into consideration, under the mode of film-mulched rice paddies, the application of CP can ensure the increase of production and emission reduction and is worth popularizing.