水稻对甲烷季节排放模式的影响(英文)

Effect of Rice Plant on Seasonal Methane Emission Patterns

在菲律宾国际水稻研究所的温室条件下调查了水稻对甲烷季节排放规律的影响。土壤在同一时间灌水,并通过同时测量处于不同生长期的水稻植株的甲烷排放量,把水稻对甲烷季节排放量的影响效应与其它因素的效应分离开来。所有的水稻品种都能在生长的早期导致一个甲烷排放高峰。这一高峰是由于土壤中易分解的有机质为甲烷细菌提供丰富的碳源,土壤中具有较高的甲烷浓度;水稻植株成为土壤中的甲烷向大气中扩散的通道。如果水稻在抽穗期或灌浆期根系分泌较多的有机质,为甲烷细菌提供足够的碳源,水稻可以导致第二个甲烷排放高峰。水稻品种之间有差异。在第二个高峰期后,甲烷的排放量开始降低,我们认为这是由于生长后期水稻根系衰老,甲烷从土壤中向根内的扩散速度减慢所致。

A greenhouse experiment was done to investigate the effect of the rice plant on seasonal methane emission patterns. The effect of the rice plant was separated from the effect of other factors by measuring methane emissions from rice plants with different ages at the same time. Soil was incubated at the same time. All the rice cultivars could at least cause one methane emission peak which is a maximum at the early growth stage. The easily decomposable soil carbon source resulted in the increase of methane concentration in soil solution. Rice plant mediated methane emission. The rice plants could cause a second maximum methane emission at the heading/filling stage if they could produce enough root exudates for methane production. Rice cultivars differed in their effect on seasonal methane emission pattern. In later growth stages, methane emissions through the rice plants decreased. This decreases in methane emission at the later growth stages were attributed to senescence of rice roots.