水稻品种对稻田CH4和N2O排放的影响

稻田被认为是温室气体甲烷(CH₄)和氧化亚氮(N₂O)的重要排放源,推广种植较少温室气体排放的水稻品种是控制稻田温室气体排放的有效措施之一。选取在太湖流域推广种植较多的16个品种为对象,通过研究其CH₄和N₂O排放情况,筛选出该区域内最适宜种植的较低温室气体排放的品种。研究结果表明,水稻的产量与CH₄排放量存在显著的线性正相关关系。在常规灌溉条件下,不管是常规品种还是杂交品种,粳稻的CH₄、N₂O累积排放量和产量都要高于籼稻。与常规品种(粳稻或籼稻)相比,杂交品种的CH₄累积排放量和产量相对较高,但N₂O累积排放量相对较低。常规粳稻中的早玉香粳和秀水134、杂交粳稻中的花优14、秋优金丰和甬优9号以及杂交籼稻中的旱优113、天优华占均具有较高的产量和较低的温室气体排放强度,有较大的推广种植价值。早玉香粳、旱优8号和旱优113为节水抗旱稻,它们在水分缺少的环境下可能会表现出更大的优势。

Effects of Rice Cultivars on CH4 and N2O Emissions from Rice Fields

Rice cultivation is an important source of methane(CH₄) and nitrous oxide(N₂O), major components of greenhouse gases(GHG). Different rice cultivars may have different GHG emission potentials. In this study, 16 rice cultivars that are currently widely planted in Taihu Lake region were selected to evaluate their CH₄ and N₂O emissions. Results showed that a significant positive linear relationship was observed between rice grain yield and seasonal cumulative CH₄ emissions. Under conventional irrigation conditions, seasonal cumulative CH₄ and N₂O emissions and grain yield were higher for japonica cultivars than for indica ones. In comparison with conventional rice cultivars, hybrid rice cultivars showed higher seasonal cumulative CH₄ emissions and grain yield, but lower N₂O emissions. Cultivars with high yield and low GHG emissions were Zaoyuxiangjing and Xiushui 134 of conventional japonica cultivars, Huayou 14, Qiuyoujinfeng, and Yongyou 9 of hybrid japonica cultivars, and Hanyou 113 and Tianyouhuazhan of hybrid indica cultivars. Furthermore, Zaoyuxiangjing, Hanyou 8 and Hanyou 113 were drought-resistant and would perform better than others under water shortage environments.