The Effect Of Climate Changes On Grain Yields In Hilly Area Of Central Sichuan Basin

In recent years, global climate change has already got comprehensive attention. Agriculture is sensitive to climate change. Under the circumstances of climatic changes, the influence of agriculture is becoming a hot spot. Taking Yanting County in hilly area of central Sichuan Basin as an example, the paper investigates the impact of climate changes on grain yields in the recent 45 years (1960~2004) on the background of climate warming.Based on meteorological observation data and the yield data of the four major crops (rice, wheat, maize and sweet potato) of the recent 45 years in Yanting County, in the paper the statistical methods are applied to analyzing the relation of climate changes and grain yield changes. Calculating the meteorological yields of grain crops, By using Lieth method, the meteorological yields of grain crops are calculated. The impact of temperature and precipitation changes on meteorological yields is predicted. Finally the agricultural development measures adapting to climate change in this area are put forward.The results show that the trend yield of food crops of Yanting County presented the increasing trend in the recent 45 years. The variation range of climate yield of food crops was relatively small before the 1980's, however after the 1980's the variation was obviously increased. In the last 45 years (1960~2004), the climate change had more effect on yields of spring crops than on that of haru crops. The effect of precipitation change on wheat yield obviously exceeded that of rice, maize and sweet potato. Solar radiation had more effect on yields of wheat and rice than on that of maize and sweet potato. The fluctuation value Pv of meteorological yield of the four crops had the consistent variation curves with the fluctuation value Yw of grain yield on the whole. It is proved that analyzing the effect of climatic factors on wheat yield based on Lieth method has applicability in Yanting County. From the effect of future climate change scenarios on meteorological yield of the four crops, precipitation has great influence on wheat yield. Temperature has great influence on the yield of rice, maize and sweet potato. Under the condition of simultaneous change of precipitation and temperature, the Warm-Wet climate is beneficial to grain production; the Cold-Dry climate is quite detrimental to grain production; the Cold-Wet climate goes against grain production in contrast with the Warm-Wet climate; the Warm-Dry climate is also unfavorable to grain production, but the yield decreasing range is less than that of the Cold-Dry climate.In order to enhance the ability of addressing climate change in Yanting County, the paper has also put forward the countermeasures of agricultural production. For instance, paying attention to disaster prevention and reduction ensures the stable yield of crops; strengthening water conservancy promotes agricultural development; enhancing research of addressing climate change for crops, and cultivating strong adaptability crops, increases grain yield; protecting ecological environment improves agriculture adaptability to climate change.