南宁市近40年寒露风演变趋势及对晚稻的影响

【目的】研究南宁市寒露风的时空分布特征、演变趋势及对晚稻的影响，为南宁市防御寒露风及晚稻生产安排提供参考。【方法】利用1970～2011年南宁市8个地面气象观测站日平均气温资料，应用倾向率分析、滑动t 检验等方法统计分析南宁市寒露风的时空分布特征、演变趋势及对晚稻产量、空秕率的影响。【结果】南宁市东北部寒露风发生频率高于其他地区，进入21世纪后南宁市寒露风总体呈减少的趋势，其中轻度寒露风呈略增加趋势，中度寒露风呈缓慢减弱的趋势，重度寒露风呈明显减弱趋势。南宁市中度、重度寒露风开始日在提前，最近10年提前了3～6 d，而轻度寒露风开始日在推后，最近10年推后了5 d。寒露风日数与整个南宁市的晚稻产量没有非常明显的关系，而晚稻空秕率与寒露风日数呈明显的正相关。【建议】在寒露风发生频率高的南宁市东北部应适当减少晚稻晚熟品种的种植面积，且应选用抗逆性强的晚稻品种种植，以减弱寒露风的影响。针对南宁市中、重度寒露风开始日近10年已提前3～6 d的特点，应做好早晚稻的种植时间安排。对于稻田面积大、劳力紧张的农户， 早、晚稻以早配迟较好， 劳动力充裕的农户则以中配迟较好， 一般不主张迟配迟。

Evolution trends of cold dew wind over the recent 40 years and its impact on late rice in Nanning City

【Objective】Three aspects including the spatial and temporal distribution characteristics, the evolution trends of cold dew wind, and its impact on late rice production were studied so as to provide references for fending off cold dew wind and late rice production planning in Nanning. 【Method】Tendency rate analysis and sliding t-test analysis were applied to study the above-mentioned three aspects using the average daily temperature statistics during 1970-2011 from eight ground meteorological stations. 【Result】The occurrence frequency of cold dew wind in northeast Nanning was higher than other regions. While the overall occurrence frequency of cold dew wind in Nanning reduced from the beginning of the 21st century, mild cold dew wind showed a slightly increasing trend, moderate cold dew wind showed slowly weakening trend and severe cold dew wind showed significantly reducing trend. Compared with ten years before, moderate and severe cold dew wind occurred in Nanning 3 to 6 days earlier, while mild cold dew wind occurrence time was 5 days later. The duration of cold dew wind had no significant relationship with late rice production in Nanning, whereas it had significantly positive correlation with sterile grain rate. 【Conclusion】In northeast Nanning with high cold dew wind occurrence frequency, planting areas of late rice should be decreased appropriately, and the varieties with strong stress resistance should be chosen to plant to reduce the influence of cold dew wind. The sowing time of earlier and late rice should be properly arranged according to the characters of cold dew wind in Nanning. The peasants short of labor with large rice-planting area should plant early rice earlier and late rice later; and the farmers with ample labor should plant moderate and late rice later, planting early and late rice later was not inadvisable.