摘要
以紫潮泥和红黄泥两种不同质地的水稻土壤作为研究对象,通过室内培养试验,分析施用硝态氮肥对N2O释放和反硝化基因(narG/nosZ)丰度的影响,并探讨反硝化基因丰度与N2O释放之间的关系。结果表明,施用硝态氮显著增加两种水稻土的N2O释放量。在72h培养过程中,施氮改变了紫潮泥反硝化基因(narG/nosZ)的丰度,但并未明显影响红黄泥反硝化基因(narG/nosZ)丰度。通过双变量相关分析发现,除了紫潮泥narG基因外,其它的反硝化基因丰度和N2O释放之间并没有显著相关性。
Nitrous oxide （N2O） is a powerful greenhouse gas with a global warming potential 296 times higher than carbon dioxide over a 100-year time period. Most of N2O is emitted from agricultural soils through microbial processes of nitrification and denitrification. In order to explore the relationship between N2O emission and denitrifying processes in paddy soil, incubation experiment was performed with purple calcareous clayey soil （P） and reddish yellow loamy soil （R） with CK and N treatments. According to N2O emission rate, soil samples were taken at 24, 48 and 72 hours which represented the growing, top and dropping periods, respectively. The abundances of narG and nosZ were analyzed using real-time PCR. The results showed that N2O emission in N treatment was significantly higher than that in CK treatment in the two paddy soils, indicating that application of NO3- greatly contributed to N2O emission. Compared the two soils treated with nitrogen, N2O flux behaved differently, in the purple calcareous soil N2O emission rates were significantly lower in 24thh in comparison with the incubation time at the 48th and 72thh which possessed similar flux rates. However, the reddish yellow loamy soil showed that the emission rate was the highest at 48thh, afterwars it dropped till 72thh the rate was significantly lower than that at 48thh. Compared to purple calcareous soil, the N2O emission in N treatment was higher in reddish yellow loamy soil, which increased 26.9%, 38.7% and 17.0% in 24thh, 48thh and 72thh, respectively. After 72 h incubation, the content of NO3--N decreased 18%and 40% in purple calcareous soil and reddish yellow loamy, indicating more NO3--N was tansformed in reddish yellow loamy than that in purple calcareous soil. The real-time PCR revealed that N application affected the abundance of the denitrifying genes in the purple calcareous clayey soil, but didn＇t obviously affect them in the reddish yellow loamy soil. For purple calcareous clayey soil, narG gene abundance in N treatment were signi
出处
《生态学报》
CAS
CSCD
北大核心
2012年第11期3386-3393,共8页
Acta Ecologica Sinica
基金
国家自然科学基金(41071181
40801098)
中国科学院百人计划资助项目(ZCX2-YW-BR-01)
关键词
水稻土
施氮
N2O释放
反硝化基因丰度
paddy soil
N application
N2O emission
abundance of denitrifying genes
