高温少雨对不同品种水稻CH_4和N_2O排放量及产量的影响

Effects of high temperature and low precipitation on CH_4 and N_2O emission and yield of different rice varieties

利用两个气候条件差异较大的稻季,研究了较高的大气温度(较多年平均升高2.6℃)和较少的降雨量(较多年平均降低36%)对6个品种(花优14、秀水134、秋优金丰、旱优8号、旱优113和早玉香粳)稻田CH4和N2O排放量及产量的影响.研究结果表明,高温少雨稻季中各品种的CH4排放量是常温多雨稻季相应品种的1.8~9.6倍(平均4.0倍).对于花优14、秋优金丰、旱优8号和旱优113来说,高温少雨相对降低2.4%~22.1%(平均12.5%)的水稻产量,其中节水抗旱稻品种(旱优8号和旱优113)平均减产8.6%,明显低于普通稻品种(花优14和秋优金丰)的16.0%.稻田N2O的排放过程短暂而急促,主要取决于施肥和水分管理措施,与气候条件或品种关系不大.CH4是稻田温室气体排放的主要贡献者.在未来气候变化情景下,稻田温室气体减排应以削减CH4排放量为主.

Two rice growing seasons with contrasting climate conditions was employed to study the effects of hightemperature(2.6℃above normal average)and low precipitation(36%lower than normal average)on CH4and N2Oemission and yield of six rice varieties(Huayou14,Xiushui134,Qiuyoujinfeng,Hanyou8,Hanyou113,andZaoyuxiangjing).The results showed that total CH4emissions of all varieties in the rice growing season with hightemperature and low precipitation were1.8~9.6times(4times in average)of that values in the normal season.Hightemperature and low precipitation condition caused yield loss by2.4%~22.1%(12.5%in average)of four varieties(Huayou14,Qiuyoujinfeng,Hanyou8,and Hanyou113),and the average reduction rate of8.6%for Water-saving andDrought-resistance Rice(Hanyou8and Hanyou113)was much lower than that of16.0%for non-WDR rice(Huayou14and Qiuyoujinfeng).The N2O emission from rice paddies was characterized by pulse and short-interval,and dependentmainly on fertilization and water management rather than climate condition or rice variety.CH4emission was the majorcontributor in greenhouse gases emission in rice paddies under both climate conditions.The results indicated that CH4emission reduction should be paid attention to mitigate greenhouse gases emission from rice paddies in global climatechange scenario in the future.