摘要
利用在江苏无锡运行的农田开放式空气C O2浓度升高(FA C E)系统平台,研究了FA C E条件对稻田中小麦秸秆分解的影响。结果表明,大气C O2浓度升高对秸秆的分解与土壤中氮肥的施用有关。在常规氮肥施用处理中大气C O2浓度升高显著降低小麦秸秆分解速率,而在高氮施肥处理中FA C E对秸秆分解没有显著影响;在常氮施肥处理中,大气C O2浓度升高显著降低秸秆中含碳物质的分解,而在高氮施肥处理中,大气C O2浓度升高的影响不显著;不论是在高氮还是常氮施肥处理中,大气C O2浓度升高对秸秆中含氮物质的分解没有显著影响;大气C O2浓度升高有增加土壤中脱氢酶活性的趋势。
Elevated atmospheric CO2 has been predicted to reduce litter decomposition as a result of CO2 -induced reduction in litter quality, and it may belead to the variety of litter decomposition. The objective of our study was to investigate the effects of elevated atmospheric CO2 on the decomposition of wheat straw in paddy field under rice/wheat rotation. This experiment was conducted in Wuxi, Jiangsu under China FACE (Free Air Carbon dioxide Enrichment) system. Two atmospheric CO2 concentrations (580±60 μmol·mol -1, 380±40 μmol·mol-1) and two N application treatments (250 kg N·hm-1, 350 kg N·hm-1) were included in our experiment. Wheat straw collected from wheat season was embedded in the same plot in paddy field. At different stages, the straw and soilwere sampled for analysis of straw decomposition and microbial activity. Elevated atmospheric CO2 significantly decreased decomposition of wheat straw at application rate of normal N, while had no significant effect at the application rateof high N. For example, within 100 days the decomposition rate under elevated atmospheric CO2 was 8.4%lower than that in ambient CO2. Under normal N fertilization elevated atmospheric CO2 decreased the decomposition of C in wheat straw,while had no effect under high N fertilization. Elevated atmospheric CO2 had nosignificant effect on the N decomposition in wheat straw under normal or high Nfertilization. FACE had a tendency to increase soil dehydrogenase activity.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2005年第2期242-246,共5页
Journal of Agro-Environment Science
基金
国家自然科学基金赞助项目(40271066)
关键词
大气CO2浓度升高
秸秆分解
氮肥处理
脱氢酶活性
elevated atmospheric CO2
straw decomposition
N fertilization
dehydrogenase activity
