Abstract:

Abstract：The features of temperature changing in various time scales in Puyang and the effect son grain production caused by the warming-up climate are analysed by the method of linear analysis .The results are as follows :the temperatures in winter and in summer float respectively with the value 0.23-0.46℃/10a and –0.05-0.11℃/10a while the yearly average is 0.14℃/10a. Every year hot days with the temperature as high as or higher than 35 decrease by the degree of 3.36 days every 10 years and cool days with the temperature as low as or lower than –10 reduce by the degree of 2005 days every 10 years .The first day when the average daily temperature keeps above 0 steadily falls 4.91 days earlier every 10 years While the last day comes 1.02 days later every 10 years . Besides , the last day when the average daily temperature keeps above 20 steadily comes 2.0 days later every 10 years. there have been 17 warm winters ever since the year 1987 in puyang , with the most typical ones happening after 1995.The breed of wheat introduced to Puyang gets weaker in winter nature with postponed sowing date ,shorter overwintering period and longer growing period .As a consequence ,plant diseases and isect pests tend to be more serious and greater amount of agricultural chemical and fertilizer have to be applied. Conclusion: the local climate is changing with the tendency of warmer winter and cooler summer. Therefore ,the damage done by high or low temperature decreases ,the efficiency of acccumulating temperature increases and plants obtain a longer growing and milking period .Ever since the mid-1990s,more events of unusual warm winter happen .The last ten years are the warmest for the past 50 years .Meanwhile ,the average yearly temperature in winter is changing with a larger amplitude ,while the temperature in spring tends to be poor in stability ,that is ,the indefinite property of temperature gains. Although there exist more advantages for the local grain production in warmer climate, disadvantages stand out at the same time. Research is necessary to ensure grain safety by pursuing gains and avoiding losses.