气候变暖背景下江西不同育秧方式双季早稻安全播期分析

明确双季早稻安全播种期及春季气候资源变化规律，是提高早春气候资源利用率和农业生产效率的重要基础。本研究基于江西省79个国家气象站过去30a（1992?2021年）2月1日?4月30日的逐日平均气温数据，系统分析了气候变暖背景下江西省不同区域不同育秧方式双季早稻50%保证率和80%保证率安全播种期的时空分布情况。结果表明，1992?2021年江西省2?4月平均气温和候平均气温呈显著逐年上升趋势，2?4月平均气温的年际变化倾向率为0.055℃·a^?1，候平均气温升高极显著时段主要集中在2月第5、第6候，3月第4、第5、第6候及4月第1候。近30a来，江西省双季早稻覆膜旱育秧、覆膜湿润育秧和直播3种育秧方式安全播种日期均呈显著提前趋势，且提前幅度从大到小依次为覆膜旱育秧＞覆膜湿润育秧＞直播。与传统播种日期相比，覆膜旱育秧赣北赣中可提前至3月上旬后期，赣南可提前至3月上旬前期；覆膜湿润育秧赣北维持3月下旬后期的传统播期或提前至3月下旬前期，赣中赣南可提前至3月中旬后期；直播方式下赣北赣中可提前至清明前2～3d，赣南可提前至3月下旬后期。

Analysis on Safe Sowing Date of Double-cropping Early Rice with Different Seedling Raising Methods in Jiangxi under Climate Warming

Ascertaining the safe sowing date of double-cropping early rice and the change rules of spring climate resources is an important basis for improving use efficiency of spring climate resources and agricultural production efficiency. Based on the daily average temperature data of 79 national meteorological stations in Jiangxi from February 1st to April 30th during the past 30 years (1992?2021), the distribution of safe sowing dates with 50% and 80% guarantee rates of double-cropping early rice with different seedling raising methods in Jiangxi under climate warming were systematically analyzed. The results showed that both average temperature and average pentad temperature increased significantly from 1992 to 2021, the climatic trend rates of average temperature was 0.055℃·y^?1, the most significant periods of climatic mean temperature increase were mainly concentrated in the 5th and 6th pentads in February, the 4th, 5th and 6th pentads in March and the 1st pentad in April, all above 1.5℃. The safe sowing dates of film-mulching dry seedlings, film-mulching wet seedlings, and direct seeding all shown a significant trend in advance, and the advance range from large to small is film-mulching dry seedlings> film-mulching wet seedling> direct seeding. Compared with the traditional sowing time, the safe sowing date of film-mulching dry seedlings in northern and central Jiangxi can be advanced to the end of early March, and which can be advanced to early March in the southern Jiangxi; the time of film-mulching wet seedlings in northern Jiangxi can maintain the traditional sowing date or be advanced to the early of late March, and in the central and southern Jiangxi this time can be advanced to the end of middle March; the time of direct seeding in northern and central Jiangxi can be advanced to 2-3 days before Qingming festival, and in the southern Jiangxi this time can be advanced to the end of late March.