近50年安徽省双季稻安全生产期变化特征

为进一步了解安徽省双季稻安全生产界限温度日期变化特征，以安徽省22个双季稻生产市(县)气象观测站1961～2017年日平均气温为基础，采用线性趋势法和Mann-Kendall非参数检验法，分析了安徽省沿江双季稻区早稻安全播种期、移栽期和晚稻安全齐穗期、成熟期及双季稻安全生长期日数、积温变化特征。结果表明:近50年安徽省沿江地区早稻安全播种期呈显著提前趋势(P<0.05)，其中薄膜育秧平均提前1.8 d/10 a，露天育秧提前1.5 d/10 a；早稻安全移栽期呈极显著提前趋势(P<0.01)，平均提前2.5 d/10 a；晚稻安全齐穗期、成熟期推迟趋势不显著(P>0.05)；安全生产期日数和积温增加显著(P<0.01)，平均增幅分别为2.6和62.7℃·d/10 a。安全生产期日数和积温增加对双季稻种植和品种选择具有积极作用，但晚稻采用直播、机插等栽种方式有遭遇低温冷害的风险。

Changing Characteristics of Safe Growth Period of Double-Season Rice in Anhui Province During Recent 50 years

In order to further understand the variation characteristic of the occurrence dates of critical temperature during safe growing period for double-season rice in Anhui Province, this paper analyzed the variation characteristics of safe sowing date and safe transplanting date for early-season rice, safe full heading date and safe maturity date for late-season rice, as well as days and accumulated temperature during safe growing period for double-season rice, which was planted in the region along the Yangtze River in Anhui province, using linear fitting and non-parameter Mann-Kendall test method, based on the data include daily mean temperature from 1961 to 2017 at the meteorological stations in 22 double-cropping rice producing counties in Anhui Province. Results showed that the safe sowing date for early-season rice showed a significant advance trend (P<0.05) in recent five decades, in which the average sowing date for seedling raising with plastic mulching was advanced by 1.8 daysper decade, and for seedling raising in open field was advanced by 1.5 days per decade. And the safe transplanting date for early-season rice significantly (P <0.01) advanced by 2.5days per decade averagely. The safe full heading date and safe maturity date for late-season rice both insignificantly delayed (P> 0.05). In addition, the days and accumulated temperature during safe growing period of double-season rice increased significantly (P<0.01), with an average increase of 2.6 days and 62.7℃·per decade respectively. The increase for days and accumulated temperature had a positive influence on planting and cultivar selection for double-season rice. On the basis of the traditional cropping pattern, the occurrence probability of damage which caused by low temperature in the duration of sowing and emergency for early rice decreased with the increase of days for safe growing period, so did it in the duration of full heading and maturity for late rice. As for the cultivar selection, it is suggested that mid-early-maturing varieties could be replaced by mid-late varieties which the duration of the growth is longer and yield is higher. However, the risk of chilling injury for late-season rice probably happened because of adopting the management of direct seeding and mechanical transplanting.