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通过室内培养试验和实时荧光定量PCR技术,研究了田间施用生物炭和有机肥对菜地土壤氧化亚氮(N_2O)排放、氨单加氧酶(amo A)和亚硝酸盐还原酶(nir S、nir K)、氧化亚氮还原酶(nos Z)基因丰度的影响,并探讨功能基因丰度对N_2O排放的影响.试验设置5个处理:CK(对照)、N(尿素)、N+BC(尿素和生物炭)、N+M(尿素和有机肥)和N+BC+M(尿素、生物炭和有机肥).结果表明,与CK处理相比,各施肥处理均降低了土壤氨氧化细菌(AOB)和氨氧化古菌(AOA)丰度,增加了nir K、nir S和nos Z基因丰度,并提高了培养期间N_2O累积排放量.与N处理相比,N+BC处理的土壤p H值提高了11.1%,并增加了AOB、AOA、nir S、nir K和nos Z基因丰度,增幅分别为105.8%、57.3%、22.0%、176.2%和204.9%,同时显著降低了培养期间N_2O累积排放量,降幅为58.1%;N+M处理增加了nir K和nir S基因丰度,增幅分别为58.8%和7.1%,对N_2O排放的影响不显著;N+BC+M处理增加了AOB、nir K、nir S和nos Z基因丰度,增幅分别为30.7%、68.7%、6.5%和84.5%,降低了N_2O累积排放量,降幅为14.4%.生物炭通过增加amo A、nir S和nir K基因丰度间接增加N_2O排放,同时通过增加nos Z基因丰度促进N_2O还原,综合效应表现为降低了菜地土壤N_2O排放.因此,通过施用生物炭改善土壤性质,增加功能基因丰度,降低土壤N_2O排放,是一种较好的N_2O减排措施.施用有机肥可以增加反硝化作用功能基因丰度,但对N_2O减排效果不显著.
The effects of biochar and organic manure on the soil N2O emission, ammonia monooxygenase (amo A) and nitrite reductase (nir S) activity in vegetable field were studied through laboratory culture experiments and real-time fluorescence quantitative PCR. , Nir K and nos Z gene abundance, and explored the effect of functional gene abundance on N 2 O. The experiment set up five treatments: CK (control), N (urea), N + BC (urea and biochar), N + M (urea and organic fertilizer) and N + BC + M (urea, biochar and organic fertilizer) .The results showed that compared with CK treatment, AOB and AOA increased the abundance of nir K, nir S and nos Z genes and increased N 2 O accumulation during the cultivation.Compared with N treatment, N + BC treatment Increased the p H value by 11.1% and increased the abundance of AOB, AOA, nir S, nir K and nos Z genes by 105.8%, 57.3%, 22.0%, 176.2% and 204.9% respectively, with a significant decrease During the cultivation period, N 2 O accumulated emissions decreased by 58.1%. N + M treatment increased the abundance of nir K and nir S genes by 58.8% and 7.1% respectively, with no significant effect on N 2 O emission. N + BC + M deal with The abundance of AOB, nir K, nir S and nos Z genes increased by 30.7%, 68.7%, 6.5% and 84.5%, respectively, reducing the cumulative emission of N 2 O by 14.4% The nir S and nir K gene abundance indirectly increased N 2 O emission and promoted the reduction of N 2 O by increasing the abundance of nos Z. The comprehensive effect was to reduce the N 2 O emission of vegetable soil so as to improve the soil properties through the application of biochar, Abundance and soil N 2 O emission was a better measure to reduce N 2 O. The application of organic manure could increase the abundance of denitrification gene, but had no significant effect on reducing N 2 O emission.