Sources of methane in China report on results 1984-1990. Annual progress report.

摘要

We have now concluded the first two phases of our research in China to evaluate emissions of methane. We believe that Chinese rice fields are the major source of methane in China and contribute significantly to the global cycle of methane. The first phase of our studies was exploratory and designed to look at a spectrum of potential sources in China that included rice agriculture, soils, urban areas, biogas pits, and other sources. This phase was also needed to establish the infra-structure and logistics for carrying out intensive field experiments in remote parts of rural China. The importance of setting up the program and the enormous logistical difficulties in carrying out experiments so far away from our base laboratory should not be underestimated. The second phase of our research involved very intensive studies of emission rates from selected Chinese rice fields. The data show that the flux rates at these fields were an order of magnitude higher than from US and European fields. An important feature of our studies is that they were done without interfering with the normal rice growing practices of the region. The results of our work also show that the flux is strongly influenced by soil temperature with a Q(sub 10) somewhere between 2 and 3 for the climatic conditions at Tu Zu. 14 refs.