生物炭和有机肥对菜地土壤N_2O排放及硝化、反硝化微生物功能基因丰度的影响  

Effects of biochar and organic manure on N_2O emissions and the functional gene abundance of nitrification and denitrification microbes under intensive vegetable production

作　　者：陈晨[1] 许欣[1] 毕智超[1] 熊正琴[1] 

机构地区：[1]南京农业大学江苏省低碳农业和温室气体减排重点实验室,南京210095

出　　处：《环境科学学报》2017年第5期1912-1920,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41471192);公益性行业农业科研专项(No.201503106);国家科技支撑计划(No.2013BAD11B01)~~

摘　　要：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.A 6-week incubation experiment with vegetable soils was conducted using real-time quantitative polymerase chain reaction（PCR） method to investigate the effects of biochar and organic manure on N2O emissions and functional marker genes of ammonia monooxygenase gene（amo A）,nir K,nir S and nos Z,which are responsible for nitrification and denitrification.The field experiment included five treatments as following,CK：control,N：urea nitrogen fertilizer,N＋BC：urea nitrogen fertilizer＋biochar,N＋M：urea nitrogen fertilizer＋organic manure fertilizer and N＋BC＋M：urea nitrogen fertilizer＋biochar＋organic manure fertilizer.Results showed that compared with the CK treatment,the treatments receiving urea（N,N＋BC,N＋M and N＋BC＋M）greatly inhibited the copies of ammonia oxidizing bacteria（AOB） and ammonia oxidizing archaea（AOA）,stimulated the copies of nir S,nir K and nos Z genes and increased N2O cumulative emissions throughout the incubation period.Compared with the N treatment,the N ＋ BC treatment significantly increased soil pH by 11.1%,and simulated the copies of AOB,AOA,nir S,nir K and nos Z genes by 105.8%,57.3%,22.0%,176.2% and 204.9%,respectively,thus decreased cumulative N2O emissions by 58.1%.Although it greatly increased nir K and nir S genes by 58.8% and 7.1%,respectively,the N＋M treatment had no significant influence on N2O emissions as compared with the N treatment.The N ＋BC ＋M treatment greatly stimulated AOB,nir K,nir S and nos Z gene copies by 30.7%,68.7%,6.5% and 84.5%,respectively,and finally decreased cumulative N2O emissions by 14.4% as compared with the N treatment.Results suggested that biochar addition decreased overall N2O emissions by enhancing the expression of nos Z gene although it enhanced N2O production by stimulating the expression of amo A,nir K and nir S genes.In conclusion,the addition of biochar could serve as an appropriate practice for mitigating N2O emissions and increasing N-cycling microbial community under intensive vegetable fields.

关 键 词：生物炭 有机肥 N2O AMOA NIRK nirS NOSZ 

分 类 号：X53[环境科学与工程—环境工程]