Climate Analysis Of Early Rice Production In Jiangxi Province

Rice is the main food crop in Jiangxi Province, accounting for about 50% of the total grain output in the province. In recent years, during the growth period of early rice in Jiangxi Province, meteorological disasters has become one of the main factors that restrict the sustainable yield of early rice in Jiangxi Province, such as continuous rain, low temperature and high temperature. This study used Jiangxi’s meteorological observation data of 12 stations from 1965 to 2012, analyzed the climatic resources characteristics of rice growing season in Jiangxi, evaluated the climate suitability of rice at different growth periods, and on the basis of meteorological disaster risk analysis of early rice’s growth period, carried out meteorological disaster risk zoning of early rice in Jiangxi. The main conclusions are as follows:(1) In the rice growing season (April to July) in Jiangxi Province, the average temperature,≥12℃ accumulated temperature, day numbers that the daily maximum temperature≥35℃ were increased with different extent, the linear trend rate were 0.226℃/10a,14.38℃/10a,0.3d/10a. The day numbers that daily minimum temperature≤20℃, sunshine hours, precipitation is not obvious in early rice’s growth season, the linear trend rate were-1.0d/10a、1.35h/10a、0.569mm/10a。In the early rice’s growing season, the average temperature,>12℃ accumulated temperature and precipitation were gradually decreased from south to north.(2) In whole growth period of early rice, the precipitation, temperature and climate suitability degree in Jiangxi Province showed a decreasing trend from southwest to northeast, the sunshine suitability degree showed high in the South and North and low in the middle of the geographical distribution. The temperature suitability degree in the whole growth period was significantly higher than precipitation, sunshine and climate. Comparison between different growth periods showed the climate suitability degree is the highest in jointing booting stage and lowest in seedling stage, and the sunshine suitability degree is the highest in grain filling stage. For nearly 50 years, the precipitation, temperature and climate suitability degree in the whole growth period showed an increasing trend of different degree and the increment rate were respectively 0.012/10a,0.013/10a and 0.006/10a. There is an obvious decreasing trend of sunshine suitability degree before 2005, then rebounded significantly since 2005. According to the calculation results of climate suitability zoning index and climate suitability degree of early rice’s growth season, the Jiangxi Province was divided as suitable area is the southwest area of Jiangxi, the sub-suitable area is the middle and northwest area of Jiangxi, poor suitable area is the northeast area of Jiangxi Province.(3) In the growing seasons of the early rice in Jiangxi province, the average occurrence frequency of the spring continuous rain is 7.3 times/10a for a single station; the spatial distribution of which is gradually increased from east to west. The areas where the spring continuous rain occurred frequently mainly included Xiushui, Nanchang, Zhanshu, jian, Yichun, Suichuan and so on. The average occurrence frequency of the low temperature disasters for a single station is only 2.2 times/10a; The spatial distribution of which is gradually increased from south to north, the areas where the low temperature disasters occurred frequently were Xiushui and Yushan. The average occurrence frequency of the high temperature disasters for a single station is up to 8.9 times/10a; the spatial distribution of which is gradually decreased from south to north, the areas where the high temperature disasters occureed frequently were Ganzhou, Suichuan, Jian and Guixi.(4) The high risk areas where suffered continuous rain in Jiangxi Province were Yichun, Nanchang and Yushan; the high risk areas of the low temperature desasters included Nanchang City, Zhangshu City, Yichun, Jian of north and middle Jiangxi; the high risk areas of high temperature desasters located in Guixi, Yushan of Northeast Jiangxi and Suining, Ganzhou of southwest Jiangxi.Nanchang City, Zhangshu City, Yichun and Yushan and other parts that located in the north of Jiangxi were suffered high risk from meteorological disaster of early rice; Jingdezhen, Xiushui, Guixi, Jiangxi Nancheng of north Jiangxi and Ganzhou of southern Jiangxi were the low risk areas, other areas were the medium risk areas.