【摘要】 以湖南省4个农业气象站点的一季稻为研究对象,基于1990—2012年逐日气象数据,精细的土壤以及田间管理记录,分析了过去23年极端高温的变化趋势,并利用校准后的CERES-Rice模型评价了高温热害的致损率,着重探讨了不同的适应性措施对缓解高温热害的作用,以期提出科学合理的减灾措施来保障我国的粮食安全。结果表明:(1)CERES-Rice能很好地捕捉本研究区不同天气和管理条件下的水稻物候期和产量,除桑植站开花期外,其余各参数的模拟误差均小于10%。(2)一季稻生育期内极端高温频发且在本世纪有增强趋势,灾损率由高到低依次为古丈>桑植>怀化>靖州,分别为10.4%,8.2%,7.5%和4%。随着气候变暖的加剧,一季稻生产将面临着日趋严重的高温热害风险。(3)选用耐高温品种产量最大可提升29.8%,但在极端高温年份,提高品种高温抗性的方法收效甚微。调节播种期会导致-25%—20%的产量波动,其中提前10 d或5 d种植均可缓解极端高温的危害。增加灌溉的贡献为1%—8%,其中6—8 cm灌水量效果最佳。极端高温期间增施氮肥的贡献稳定且显著,平均增产2%—20%,80—100 kg/hm~2的施氮量能带来较为理想的避热增产效果。更多还原

【Abstract】 By applying CERES-Rice, we firstly assessed the yield losses of single rice from extreme high-temperature events（EHTEs）, and then tried to find the potential adaptation measures at four agro-meteorological stations in Hunan Province based on detailed information（including daily climatic observations, fine soil, field management and crop growing records from 1990 to 2012）. We found that CERES-Rice was a suitable tool for the study due to the low simulated errors（<10%）, with the exception of simulated flowering days at Sangzhi station（13.22%）. EHTEs were occurred frequently during single rice growth seasons and a significant increased trend was observed during the 21^st century. Moreover, the yield losses caused by EHTEs were ordered by Guzhang > Sangzhi > Huaihua > Jingzhou, with the corresponding values of 10.4%, 8.2%, 7.5%, and 4%, respectively. Finally, several potential adaptation measures were evaluated by the calibrated CERES-Rice, and we found that（1） the yield could be enhanced by 29.8% through planting a cultivar with a higher temperature tolerance coefficient. However, such a cultivar will show little effect on enhancing yield in the years with extremely high temperatures.（2） Adjusting sowing dates would cause a yield variability ranging from-25% to 20%, with a positive effect when planting 5 or 10 days in advance.（3） Increased irrigation would alleviate heat damage and increase yield by 1%—8%, with the best effect when irrigating approximately the depth of 6—8 cm.（4） Applying nitrogen fertilizer during EHTEs would contribute significantly to the final increased yields of 2%—20%. On average, 80—100 kg/hm² nitrogen application would produce an ideal effect.更多还原