Study On The Effect Of Climate Change On Maize Yield In Liaoning Province

In order to seek the impacts of climate warming on the yield per unit area of maize in recent 20 years in Liaoning Province, a study was conducted for providing a theoretical basis for the production management of maize in Liaoning Province. According to the temperatures in summer, the eight typical cities from the main growing regions in Liaoning Province were divided into I area and II area. Making use of the meteorological observation date, the maize yield and the area information in recent 20 years in Liaoning Province, the relationships between climate factors (temperature, precipitation, sunshine hours and effective accumulated temperature) and the yield per unit area of maize during the maize growth season were analyzed by correlation and regression analysis and other statistical methods. The major findings are as follows:(1) In recent 20 years, the average temperatures in Liaoning Province during maize growth season were rising significantly. Climate trend rates were 1.055℃/10a. Different regions had different situation about the temperature range, but they showed the rise of temperature as a whole. There were significant changes which appeared fluctuation trend in the precipitation, and different regions had different and significant changes in the precipitation. I area’s precipitation more than II area, I area showed a downward trend, but II area appeared an upward trend, the whole trend of precipitation was downward. The sunshine hours was declining in volatility, especially in Tieling area. As for the accumulated temperature, it changed in volatility and showed an increased trend in general.(2) In recent 20 years, the yield per unit area of maize in Liaoning Province had an upward trend. The yield per unit area of I area maize and II area maize had an upward trend, but the speed of growth of I area slower than II area. Most of the research areas in this article, there was a significantly negative correlation between the average temperature and the yield per unit area of maize, it showed that the yield per unit area of maize will decrease with the rising average temperature. There was also a significantly negative correlation between the effective accumulated temperature and the yield per unit area of maize. Dalian, Zhaoyang and Fuxin’s sunshine hours had a significantly negative correlation with the yield per unit area of maize, only Fuxin’s precipitation had a significantly positive correlation with the yield per unit area of maize. Premise of the temperature increase, the precipitation in Liaoning Province will be a downward trend, but the base was not large, which increased regional drought and affected the growth of maize.(3) Generally increase in temperature is beneficial to early spring sowing of maize, but it will also affect the division of the region for planting. The changes of soil and environment and the decreased precipitation will aggravate the drought, which will limit the maize production. So when we focused on the adjustment of sowing time and the variety combination, we could depend on the construction of water conservancy works to enhance the coordination and supply in Liaoning Province. We can spread the cultivation techniques about water-saving, and also can choose the drought-enduring and adverse-resistance maize varieties to improve the yield per unit area of maize.