Abstract:

Based on the daily data of the meteorological stations in central Hunan from 1980 to 2017, combined with the double-cropping early rice yield data from 2007 to 2017 and the observation data from 3 rice meteorological observatories, the M-K mutation was used to analyze the adjustment of sowing date of double-cropping early rice in central Hunan, and the effects of agro-climatic factors at different growth stages on the yield of double-cropping early rice was analyzed by grey correlation method, four major agro-climatic indicators were selected, and their adaptive adjustments were explored. Finally, the climate index suitability evaluation model was used to verify the agro-climatic indicators. The results showed that the sudden change of the initial day stabilize through 10 °C during the spring sowing was occurred in 1997 from 1980—2017 in central Hunan. The sowing date of the double-cropping early rice in central Hunan could be advanced from the late March to early April in the 1990s to mid-March to early April, about 7 days in advance. The thresholds of major agro-climatic indicators affecting the yield of double-cropping early rice were identified by grey correlation method and polynomial method: accumulated temperature of 10℃≥1 546.9 ℃ from jointing to maturity stage, sunshine hours≥291.1 h from jointing to maturity stage, and accumulative temperature of 10℃≥ 476.8 ℃ at paddy field stage, and the mean temperature≥19.8℃ during the transplanted to delivery period. Finally, the verification results of climate index suitability evaluation model showed that these agricultural climate indicators were suitable for practical production of double-cropping early rice in central Hunan. It provided theoretical support for the establishment and updating of the climate index system, the production forecast and the adjustment of planting system of double-cropping early crops in central Hunan.

Key words: double-cropping early rice, agro-climatic indicators, sowing date adjustment, grey correlation method, suitability evaluation

摘要：

利用湘中地区1980—2017年逐日气象资料，结合2007—2017年湘中地区双季早稻产量资料和3个水稻气象观测站的观测数据，采用M-K突变分析了湘中地区双季早稻播种适宜期调整，同时通过灰色关联法分析了双季早稻各生育期内农业气候因子对产量的影响，筛选出4个主要农业气候指标，并探索其适应性调整，最后利用气候指标适宜度评价模型进行验证。结果表明，湘中地区1980—2017年春播期稳定通过10 ℃初日的突变点在1997年，湘中地区双季早稻的播期可由上世纪90年代制定的3下旬至4月上旬，提前至3月中旬至4月初，提前约7 d；通过灰色关联法和多项式法确定影响双季早稻产量的主要农业气候指标及其阈值分别是：拔节至成熟期10 ℃以上积温≥1 546.9 ℃、拔节至成熟期日照时数≥291.1 h、秧田期10 ℃以上积温≥476.8 ℃和移栽至分蘖期平均气温≥19.8 ℃；最后气候指标适宜度评价模型验证结果表明，这些农业气候指标适宜应用到湘中地区双季早稻的实际生产中。本研究结果为湘中地区双季早稻气候指标体系的建立和更新、产量预报和种植制度的调整提供了理论支撑。

关键词: 双季早稻, 农业气候指标, 播期调整, 灰色关联法, 适宜性评价