关键词: 气候变暖, 育秧方式, 双季早稻, 安全播期

Abstract: 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.

Key words: Climate warming, Seedling raising method, Double-cropping early rice, Safe sowing date