Diurnal Change in Methane Flux from a Rice Paddy related to the Soil Temperature
Diurnal Change in Methane Flux from a Rice Paddy related to the Soil Temperature
复制标题
与土壤温度相关的稻田甲烷通量日变化
DOI：
10.2480/agrmet.54.329
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
I. Nouchi
中科院分区：
文献类型：
--
作者：
T. Hosono;I. Nouchi
许多研究发现稻田甲烷排放通量日变化较大。甲烷通量变化较大的原因被认为是由于土壤中甲烷产生速率和/或水稻植株的运输能力的变化。为了更好地了解甲烷通量日变化的机制，研究了甲烷生产和甲烷输送对甲烷通量日变化的影响。使用流通室法连续测量稻田甲烷通量2天。在此期间，还每2-4小时测量土壤水中的甲烷浓度。利用所获得的数据，净甲烷生产率计算从稻田中的甲烷的质量平衡，而水稻植物的甲烷运输的电导率计算通过使用扩散模型作为甲烷的运输能力。结果表明，水稻植株的净甲烷产生速率和甲烷输送电导率均表现出明显的日变化，这与土壤温度的日变化有关。通过与甲烷通量、甲烷产生速率、水稻电导率和土壤温度的日变化模式的比较，认为甲烷通量的变化主要是由于水稻电导率随土壤温度的变化而变化。
Large diurnal variations in methane flux from rice paddies have been found in many studies. The cause of the large variations in methane flux was considered to be resulted from changes in methane production rates in the soil and/or the transport capacity of rice plants. To get better information about the mechanism of diurnal variation in methane flux, effects of both methane production and methane transport on the diurnal variation in methane flux were investigated. Methane flux from a rice paddy was continuously measured using a flow-through chamber method for 2 days. Methane concentration in the soil water was also measured every 2-4 hour during the period. Using the data obtained, net methane production rate was calculated from the mass balance of methane in the rice paddy, while the conductance of rice plants for methane transport was calculated by using a diffusion model as the transport capacity of methane. As a result, both the net methane production rate and the conductance of rice plants for methane transport clearly showed large diurnal variations, which were associated with the diurnal change in soil temperature. From the comparison with the diurnal patterns among the methane flux, the methane production rate, the conductance of rice plants and soil temperature, the change in the methane flux is considered to be mostly attributed to the changes in the conductance of rice plants for methane transport depending on the soil temperature.