Influence Of Meteorological Factors On Growth And Yield Of Rice In Early Season In Changsha Region

Since the problem of global warming has become more serious, climate change produces prolong effects on every aspect of human life, especially on agricultural activities. Based on the State Meteorological Observed Station in Mapoling, Changsha in Hunan province, we observed the growth of rice in early season and its yield structure between the years of 2012-2014 under the field conditions, and initially combined the data of meteorological information to analyze the change of the growth of rice. The results showed that the major meteorological disasters were high temperature and dry hot wind which appeared on the heading and milk stage, and overcast and rainy that emerged on returning green stage or tillering stage to jointing stage. The Meteorological disasters had no significant effects on crop height in each year. Plant density increased from recovering date to milk stage. In the year of 2014, plant density was relative low relative to other years, mainly affected by rainy sparse sunlight. The leaf area index increased from regreening stage to booting stage and got the maximum value in booting stage, and then decreased slightly for each year. Both in 2012 and 2013 year, the leaf area index in booting stage was beyond 6, more than that in 2014 year, which was also caused by rainy sparse sunlight, meanwhile, in the year of 2014, the dry matter accumulated slowly, whereas the filling rate was the fastest. As to the yield structure, considering above effects from meteorological disasters for each year, the thousand seed weight of rice was the highest in 2014 year, and lowest in 2012 year. The real rice yield was the highest (871.6 g m^-2) in 2013 year, and lowest of percentage of empty grain and blighted grain, however, both of them presented the highest value in 2012 year.The final yield of rice in early season was the compressive result of various meteorological damages, therefore, practically it should be noticed the interactive and comprehensive effects when relating the meteorological factors to yields. The conclusions derived from this study can help understand the growth of rice in early season in recent years, and provide a reference for reasonable plantation and avoid the bad meteorological conditions. In addition, it can offer detain meteorological information of the growth of rice in early season for model simulation.This study proposed that rice planting in early season in Changsha was affected greatly by meteorological factors, particularly in the reproductive stage, and high temperature and rainy weather should be paid more attention by the farmers.