Abstract: The characteristics of methane release as well as biological mechanism in paddy soil were studied by methods of soil column and in situ field. The results showed that the amounts of methane released were up to maximum during vigorous tillering stage of both early and later rice, then gradually decreased. Both organic and inorganic ferilizers stimulate the release of methane from paddy soil, however, organic manure induce more methane release than urea. The most active part of methane formation was the root system undisturbed and combined closely with soil. More than 80% of methane was released by rice plant i methanogenic bacteria adhered to root surface. The result also showed that the amounts of methanogenic bacteria, anaerobic celluloclastic and methane-oxidizing bacteria as IVFA in rhizosphere soil were higher than that in non-rhizosphere soil. 

Key words: rice paddy field, rice plant, methane release, methanogenic bacteria, methane-oxidizing bacteria