施铁对普通野生稻田甲烷排放的影响

Mitigation of methane emission from Oryza rufipogon paddy soil with a higher Fe2+concentration

为了探究施铁对普通野生稻田甲烷的减排效果,对1个根表铁膜形成能力较强的普通野生稻居群进行了水泥池小区对比试验,观测了施铁处理和对照的CH_(4)排放速率、土壤孔隙水Fe^(2+)浓度和根表铁膜。结果表明:施铁导致CH_(4)总排放量减少了29.51%,在普通野生稻生长前期CH_(4)减排效应尤为明显。移栽后第19天,施铁小区的土壤孔隙水Fe^(2+)浓度为0.57 mmol·L^(−1),显著大于对照小区。根生物量和单株根表铁膜数量在施铁处理和对照之间的差异随植株年龄增大而增大。因此,施铁措施对具有厚铁膜潜力的普通野生稻居群的CH_(4)减排能起到明显的促进作用。

In order to explore the effect of Fe amendment on methane emission from Oryza rufipogon paddy soil,a comparison experiment was conducted in concrete ponds using a Oryza rufipogon population with higher capacity to form iron plaque on roots.The 11-day-old seedlings were transplanted to the rice paddy soil which was previously treated with or without addition of ferrihydrite at a rate of 0.7 g Fe/kg dry weight soil and already planted 6 growing seasons of rice under continuous flooding regime.Methane emission rate,Fe^(2+)concentration in soil pore water,root biomass and iron plaque on roots were measured.The experimental results showed that the methane emission in the Fe-amended pond during the period of 19-75 days after transplanting was reduced by up to 29.51%,comparing to control.Methane suppression observed by Fe amendment occurred only in the early growing season.There was a significant difference in Fe^(2+)concentration in soil pore water between two treatments only at 19 days after transplanting over the investigation period.The difference in both root biomass and amount of iron plaque per plant between Fe-amended treatment and control increased with age of plants.The present study suggests that Fe amendment can effectively mitigate methane emission from Oryza rufipogon plants with potential to have much more iron plaque on roots.