| Project/Area Number |
06556045
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
生物環境
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| Research Institution | Tokyo University of Agriculture |
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Principal Investigator |
NAGANO Toshihide Tokyo University of Agriculture, Faculty of Agriculture, Professor, 農学部, 教授 (10012006)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAKURA Tadasi The University of Tokyo, Graduate School of agricultural and Life Science, Profe, 農学部, 教授 (50011929)
UEKI Katsuji Yamagata University, Faculty of Agriculture, Professor, 農学部, 教授 (10111337)
UEKI Atsuko Yamagata University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (60143088)
ISHIDA Tomoyasu Utsunomiya University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (00159740)
北宅 善昭 大阪府立大学, 農学部, 助教授 (60169886)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥10,900,000 (Direct Cost: ¥10,900,000)
Fiscal Year 1996: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1994: ¥6,500,000 (Direct Cost: ¥6,500,000)
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| Keywords | methane / green house effect / gases flux measuring / eddy accumulation method / Paddy field / メタンフラックス / 二酸化炭素フラックス / ガスサンプリングシステム / 地球温暖化 / CO_2フラックス |
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| Research Abstract |
The fluxes of carbon dioxide and/or methane are considered to have influences upon global environmental change. The chamber methods are genrally used to measure the biosphere/atmosphere fluxes of the gases, especially of methane. The measured values, however, widely varies spatially. The site spatial variability makes it difficult to estimate gases fluxes from a field or ecosystem. The micrometeorological methods integrate large surface area thereby reducing the spatial variability problem. The eddy correlation method is most reliable one to estimate tha gas fluxes. However, the method requiers fast measurements of the gas concentration considered for flux shorter than 5Hz, which are almost impossible for most gases using the sensors presently existing. Recently, the eddy accumulation method was theoretically proposed to measure scalar fluxes using conditional gas sampling. The eddy accumulation method by passes the need for fast measurements of gas concentration. We have developed a new system based on this theory, checked its reliability, and measured methane flux in the paddy filed.
In various plots of rice paddy fields supplied with different amounts of rice straw or compost, growth of rice plants, soil Eh methane concentrations in soil gas, and methane emission rates measured over the cultivation perriod. The number of tiller of rice plants increased during June at different rates depending on the plots. The methane concentration in the soil gas were more than 40% in the plots applied with rice straw even soon after the transplanting. At the tillering stage the concentrations were more than 30% in almost all the plots. The methane emission rates were very low soon after the transplanting and markedly increased at the maximum tiller stage. It was suggested that the difference of growth of rice plants affects the soil environment of paddy filed and also the methane emission rate.
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