Abstract: Songnen plain is an important commodity grain base in China, which has characteristics of suitable climate and fertile soil. It is important for national food security to study impact of climate change on crop production in this region. Based on observational data of reference period(1961−1990) in Songnen plain, statistical method was applied to correct deviation between simulation data and observation data, five-day moving average method was used to calculate accumulated temperature ≥10℃, and characteristics of spatial and temporal changes of agricultural climate resource indicators in next 30 years in study area relative to reference period were analyzed. The results showed that under two emission scenarios of RCP4.5 and RCP8.5, average temperature in most parts of Songnen plain in next 30 years would be between 4−8℃, which was 2.5−2.8℃ higher than reference period, and temperature increase in northern region was greater than that in southern region. In addition, accumulated temperature ≥10℃ in most areas was between 3000−3700℃·d, and increase of 500−550℃·d and 600−670℃·d under two scenarios respectively, of which increase in some areas in south exceeded 670℃·d. Annual precipitation was between 460−580mm in most places, with increments ranging from 50mm to 90mm. In terms of spatial distribution, precipitation increment in south was more than that in north. Rainfall increases in southern region exceeded 90mm, while annual increase in northern region was less than 50mm. Rainfall increments in the same area of two scenarios showed that RCP4.5 was more than RCP8.5. Compared with baseline period, annual radiation had been reduced by 85−100MJ·m−2, and radiation during growing season had been reduced by 10−40MJ·m−2, and change trend was not obvious. In summary, agricultural climate resources in Songnen plain would show a trend of overall improvement in the future, and crops could be planted for a relatively longer period in the future. Therefore, crops with longer growth periods should be planted appropriately to avoid increase of temperature, which would shorten growth period of existing crops and cause yield lower situation occurred. At the same time, the research results have guided significance for agricultural production such as adjusting planting structure, changing planting measures, and selecting crop varieties, so as to achieve purpose of fully utilizing of climate resources and increasing crop yields.

Key words: Songnen plain, Climate change, Thermal resource, Precipitation, Radiation, RCPs scenarios