不同栽培措施对水稻田甲烷释放、甲烷产生菌和甲烷氧化菌的影响

本文报导不同栽培措施下水稻田甲烷释放的特性和甲烷产生菌、甲烷氧化菌的数量、种类。结果表明,水稻田的甲烷释放,无论是早稻还是晚稻,成活期每天的释放量较少,随着生长逐渐增加,至分蘖期达到最高,随后又逐渐减少,长期淹水和施用高量氮肥或有机肥可以明显地增加水稻田的甲烷释放量。水稻田土壤中产甲烷细菌的数量湿灌溉少氮处理少于其他各处理,其他各处理间无明显差异。早稻生长前期较后期土壤中的产甲烷菌数量低2—3个数量,晚稻生长中期略高于生长前期和后期。甲烷氧化菌数量在早稻生长期间从10~3～10~4/g干土增加到生长后期的10~8/g干土。在晚稻生长期间维持在10~8/g干土。产甲烷细菌的种类主要为甲烷杆菌属(Methanobacterium)和甲烷八叠球菌属(Methanosarcina)的种。甲烷氧化菌主要为杆状,除甲烷外还能利用其他基质的兼性异养型甲基营养型细菌。

Effect of Different Cultivation Conditions on the Release of Methane, the Amounts of Methanogens and Methane- Oxidizing Bacteria in Rice Paddy Soil.

The effect of different cultivation conditions on the release of methane, the amounts of methanogens and methane-oxidizing bacteria in rice paddy soil are reported. After rice seedlings was transplanted, the amount of methane released from rice plant was gradually increased with rice plant growth and reached to the maximum at flourishing tillering stage. After this stage it was gradually decreased. The amount of methanogens in rice paddy soil was 2-3 orders of magnitude lower during the earlier stages than that during the latter stages in earlier rice. However, the amount of methanogens was slighly higher during the middle stage than that during the earlier and latter stages. The predominant methanogenic bacteria isolated from rice paddy soil belonged to Methanobacterium and Methanosarcina. The amount of methane-oxidizing bacteria was about 103-104/g dry soil during the earlier stage and 108/g dry soil during the latter stage in earlier rice. Then, it was kept at about 108/g dry soil in latter rice. Four strains of methane-oxidizing bacteria were isolated and belonged to faculative heterotrophic methy-lotrophs.