不同水分管理下稻田土壤CH_4和N_2O排放与微生物菌群的关系

Relationship between CH_4 and N_2O emissions and related microorganism populations in paddy soils under different water management regimes

采用MPN计数法对黑土 (海伦 )和草甸棕壤 (沈阳 )稻田生长季 4种微生物菌群数量进行了测定 ,同时采用封闭式箱法对CH4和N2 O通量进行观测 ,以深入了解稻田生物源温室气体排放的微生物学过程 .两地试验田均采用长期淹灌与间歇灌溉两种不同水分管理 .对实验结果多元回归分析 ,结果表明 ,海伦与沈阳两地稻田两种水分管理条件下CH4通量季节变化与产甲烷菌数季节变化存在极显著正相关关系 .沈阳稻田生长季CH4通量季节变化与甲烷氧化菌数季节变化具有显著正相关性 .间歇灌溉条件下黑土稻田N2 O通量与反硝化菌数呈显著性正相关关系 .两种水分管理条件下沈阳稻田N2 O通量与硝化菌数具有显著正相关关系 .间歇灌溉条件下沈阳稻田N2

Methanogens,methanotrophs,nitrifiers and denitrifiers are the important microorganisms in the production and consumption of CH 4 and N 2O in soil. In order to understand the microbial processes related to the two greenhouse gases in paddy soil,the four bacteria groups in phaeozem (Hailun) and burozem (Shenyang) were surveyed during rice growth season by using MPN counting technique. The CH 4 and N 2O emissions were measured with closed chamber method. Two different water management regimes,i.e.,continual irrigation and intermittent irrigation,were used for the two paddy soils. The results of multiple regression analysis showed that there was a significantly positive correlation between CH 4 emission and methanogen population in both phaeozem and burozem under two water management regimes. In the soil of Shenyang,there was a significantly positive correlation between CH 4 emission and methanotroph population. The N 2O emission was significantly correlated to the denitrifier population in both phaeozem and burozem under intermittent irrigation,and in the soil of Shenyang,there was a significantly positive correlation between N 2O emission and nitrifier population under two water managements.