Impact of altered flooding and crop rotation regimes on microbial communities and activities involved in nitrogen fixation and nitrogen cycling

我们将研究高地玉米和淹没水稻种植之间的作物轮作和淹水和非淹水条件下的甲烷生产过程中所涉及的产甲烷微生物群落的组成的影响。这将通过以下方法来完成：根有机碳、土壤有机碳、乙酸盐、CO2和CH 4中的δ 13 C分析;使用13 C-CO2的脉冲标记实验;以及土壤和根际产甲烷古菌群落的16 S rRNA基因的分子分析。因此，我们期望获得碳的周转率，不同途径的相对贡献CH 4生产和相对贡献的根与土壤有机质来源的碳CH 4生产，所有这些参数的组成有关的产甲烷古菌群落。这项研究将显示作物轮作将如何影响社区组成和参与温室气体甲烷的生产和排放过程。

We will study the effect of crop rotation between upland maize and submerged rice cultivation and between flooded and non-flooded conditions on the processes involved in methane production and on the composition of the methanogenic microbial community. This will be done by a combination of δ13C analysis in root organic carbon, soil organic carbon, acetate, CO2 and CH4; of pulse-labelling experiments using 13C-CO2; and of molecular analysis of the 16S rRNA gene of the methanogenic archaeal community in soil and rhizosphere. As result we expect to obtain turnover rates of carbon, the relative contribution of different pathways to CH4 production and the relative contribution of root-derived versus soil organic matter-derived carbon to CH4 production, all these parameters in relation to the composition of the methanogenic archaeal community. The study will show how crop rotation will affect community composition and processes involved in production and emission of the green-house gas methane.