研究成果報告書 E97B1611.HTM

検索画面に戻る Go Research

(442Kb)

[B-16.1.1 Studies on Development of Reduction Techniques for Methane and Nitrous Oxide Emissions from Agricultural Fields]


[Contact Person]

Haruo Tsuruta
Head
Laboratory of Environmental Impact Assessment, Department of
Environmental Planning, National Institute of Agro-Environmental Sciences,
Ministry of Agriculture, Forestry, and Fisheries
3-1-1 Kan-nondai, Tsukuba, Ibaraki 305-8604 Japan
Tel:+81-298-38-8276, Fax:+81-298-38-8199
E-mail:tsuruta@niaes.affrc.go.jp


[Total Budget for FY1995-FY1997]

42,883,000 Yen (FY1997;14,126,000 Yen)


[Abstract]

  1. Survey of organic matter management in local paddy fields in Thailand showed that biomass of weeds grown during fallow period was important for methane(CH4)emission during cultivation period as well as that of residual rice straw. The organic matter application experiment in lysimeter paddy fields indicated that the treatment of rice straw and stubbles at harvest had a significant effect on CH4emission from paddy fields in next cultivation period
  2. A laboratory experiment showed that the temperature around the root greatly affected the CH4 transport process in rice plants. And the gas entrapped in the soil could enter into the rice body directly from the part of the stem near the base which is beneath the soil surface due to gas pressure in the gas phase resulting from the pressure exerted by the standing water.
  3. The nitrous oxide(N2O) emission rates from maize upland fields with fertiliser application at four experimental sites in the wet seasons of Thailand were in a range of 0.08-0.44 % of the total application rate of nitrogen to the fields. The N2O emission ratio in the tropics of Thailand was nearly equal to that in Japan located in the temperate zone.
  4. The N2O emission rates from rice paddy fields during a cultivation period in three experiment stations(Fengqiu, Nanjing, and Yingtan) in China were in a range of 1.7-472 mgN m-2,h-1. The flux of N2O was greatly enhanced after the final water drainage, while CH4 stopped to emit, and the total emission rates of N2O and CH4 were negatively correlated. Hence, the emission of CH4 and N2O was in the same relationship of "trade-off" as in Japan.

[Key Words]

Methane(CH4), Rice Paddy Fields, Nitrous Oxide(N2O), Fertilized Upland Fields, Reduction Technique for Emission