摘要
在实验室条件下,采用密闭、淹水、充N2的严格厌氧培养方法研究了NO3-N浓度对亚热带土壤反硝化潜力和产物组成的影响。研究表明,在NO3-N浓度为10～200 mg/kg范围内,该土壤的反硝化势变化于0.024～0.224 mg/(kg h)之间,随着NO3-N浓度的增加而呈显著线性增加(R2=0.94,P<0.01)。N2O始终是反硝化的主要产物,占反硝化产物的56%～92%;NO是次要产物,占6%～40%。在野外原位状态下,土壤的还原条件难以达到供试实验室条件,由此估计,亚热带森林土壤反硝化的主要产物并非N2,而是N2O和NO,这可能是该类土壤虽反硝化作用弱,但N2O排放量大的主要原因。
The effects of soil nitrate concentration on denitrification potential and products＇ composition were studied under laboratory culture,using sealed,submerged and anaerobic incubation method.The results showed that denitrification potential increased with the rise of nitrate concentration and a good linear relationship （R2 =0.94,P＜0.01） presented between them in the range of nitrate concentration of 10 to 200 mg/kg.The denitrification potentials of the experimented samples ranged from 0.024 to 0.224 mg/（kg.h）.N2O was always the dominant product of denitrification,accounting for 56％-92％ of the total denitrification products,and NO was a minor product of denitrification,accounting for 6％-40％.Soil reduction condition of in-situ field should be not as strong as laboratory incubation.Therefore,the main end product of subtropical acid forest soils of China is not N2 but N2O and NO.This conclusion may explain the reason why this soil has a large N2O emission regardless of its low denitrification rate.
出处
《土壤》
CAS
CSCD
北大核心
2013年第5期815-820,共6页
Soils
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-QN405)
国家自然科学基金重点项目(40830531)
土壤与农业可持续发展国家重点实验室开放基金项目(0812000030)资助
关键词
乙炔抑制
厌氧培养
反硝化
硝态氮浓度
Acetylene inhibition
Anaerobic incubation
Denitrification
Nitrate concentration
