温度对农田N2O产生与排放的影响 |
摘要点击 4018 全文点击 3953 投稿时间:1997-01-21 |
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中文关键词 N2O排放 温度 排放通量 稻麦轮作系统 农田 太湖地区 |
英文关键词 N2O emission temperature N2O production rice-wheat ecosystem emission fluxes farmland |
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中文摘要 |
以华东太湖地区的水稻-冬麦轮作农田为研究对象,采用基于箱法-气相色谱法的自动连续观测系统,对整个轮作周期的N2O排放和温度进行了同步自动连续观测,同时,在实验室开展了一系列的模拟实验,以研究N2O产生与排放过程的温度效应。实验研究结果表明,在土壤湿度适宜的一定温度范围内,N2O排放通量对温度的依赖性可用指数函数F=Aeat来描述;轮作周期内显着N2O排放发生的频率随温度的变化呈正态分布,67%的排放量都集中在15-25℃温度范围内;在旱地阶段,温度是影响N2O排放季节变化的关键因子,而在水田阶段则不然;水田和旱地N2O排放具有相同的规律性日变化形式,但后者达到极大值的时间要比前者延迟约3h。 |
英文摘要 |
N2O emission fluxes from a rice-wheat rotation ecosystem of the Taihu Region in Southeast China and temperature of air and soil were simultaneously measured with an automated system to understand the effects of temperature on N2O emission. The principle of this automated system for N2O emission measurement was based on static chamber techniques and gas chromatography with an electronic capture detector. Additionally,some simulated experiments were also undertaken in laboratory to study temperature impacts on N2O production. Based on the results from this experimental study,conclusions as following could be drawn. N2O emission flux from fields with suitable moisture is exponentially correlated to top soil temperature. The occurring frequency of significant N2O emission in a rice-wheat rotation cycle versus top soil temperature is in normal distribution,with 67% of the total N2O amount emitted within 15—25℃. Temperature is rather a key factor regulating N2O emisson from wheat fields. However,on significant relationship between temperature and seasonal variation of N2O emission from rice field was found.Although the diurnal maximum of N2O emission from rice fields which occurs simultaneously with diurnal temperature peak appears about 3 hours earlier than that from wheat fields,the diurnal variation patterns from both rice and wheat fields are the same. |
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