为探讨玉米田土壤中氧化亚氮(N2O)释放规律以及不同因素对其影响。采用自行设计的土壤释放气体常压培养模拟装置,通过设置不同的氮肥施用量、土壤含水量、培养温度及土壤酸化等处理,进一步明确了N2O释放特性及对环境因素的响应。结果表明：纯氮施入量由70 mg/kg增加至300 mg/kg,N2O释放总量分别增加了32.9%(对照土壤)和21.2%(酸化土壤)。含水量由15%增加至25%,N2O释放总量分别增加了26.5%(对照土壤)和16.1%(酸化土壤)。不同培养温度对比发现：N2O释放总量变化趋势为25℃处理>35℃处理>15℃处理,25℃处理与15℃处理相比,N2O释放总量分别增加了12.7%(对照土壤)和20.0%(酸化土壤)。与对照处理相比,酸化处理N2O释放总量平均增幅均高于5%。本文采用的常压密闭培养模拟装置与传统密闭装置相比,与生产实际更为接近,所得结论可信度更高,前者的N2O释放量高于后者。培养前期是N2O释放最为集中的时期。在本文试验所设定的条件范围内,增施氮肥、提高含水量、土壤酸化导致N2O释放强度增大,另外,合适的培养温度有利于N2O释放。因此,应合理施肥与灌溉,降低N2O污染风险。
英文摘要:
To study the release rule of N2O and the influence of different factors on N2O release. This paper attempted to use the atmospheric simulation cultivation of releasing gas in order to further investigate the release rule of N2O and the influence of environmental factors on N2O release by set up different nitrogen application rate, soil moisture content and temperature and soil acidification disposal. The amount of nitrogen application were from 70 mg/kg to 300 mg/kg. With the increase of nitrogen application, total N2O release from the control and the acidified soil were increased by 32.9% and 21.2%, respectively. While the soil moisture content were increased from 15% to 25%, total N2O release from the control and the acidified soil were increased by 26.5.% and 16.1%. Through comparing to different temperatures, we found that the changed trend of total N2O release was 25℃treatment >35℃treatment >15℃treatment. The maximum value and the minimum value of N2O release occurred when the culture temperature is 25℃ and 15℃,respectively. And total N2O release from the control and the acidified soil were increased by 12.7% and 20%. The increased of N2O release from soil acidification were higher than 5% when compared with the control. The atmospheric simulation cultivation of releasing gas used in this article was more close to actual production comparing with conventional obdurate, which can enhance the credibility of conclusion. Total N2O release using the former were higher than using the latter. The early stage of the culture is the most concentrated period of N2O release. Within the scope of conditions set up in this paper, the N2O release were increased along with increased nitrogen application and the soil moisture content. In addition, soil acidification disposal and appropriate culture temperature can also lead to the increase of N2O release. This suggests that the rational fertilization and irrigation are effective ways to reduce N2O emissions in order to reduce environmental risk.
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