基于CERES-Rice模型的湖南省一季稻极端高温损失评估及适应性措施

Yield losses caused by extreme high-temperature events and potential adaptive measures for single rice in Hunan Province based on the CERES-Rice model

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/hm2的施氮量能带来较为理想的避热增产效果。

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 21st 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.