Study On Temporal And Spatial Distribution Characteristics Of Wheat Yield And Its Response To Climate Change Based On APSIM

In order to ensure global food security, it is necessary to increase the yield of main grain crops such as wheat to meet the demand. However, agriculture is the largest industry affected by climate change, the impact of climate change may make it challenging, climate change has a significant impact on the growth and yield of wheat in all parts of the world. The wheat planting time is long and the distribution is wide in Inner Mongolia area, with the change of global climate and the increasing of global warming, The light, heat, water and other environmental resources of Inner Mongolia region have been changed obviously, all these changes have a direct impact on the growth and development of spring wheat in Inner Mongolia area. In this paper, the parameters and validity of the APSIM model are tested based on the daily meteorological data and crop field observation data during 50 years of 1961-2010.Simulating the growth period and yield of spring wheat.analysising the spatial and temporal distribution characteristics of wheat yield, the change characteristics of agricultural meteorological resources and the key factors affecting the development period and yield of spring wheat in Inner Mongolia during the past 50 years, discussing the esponse of development and yield to environmental factors.Results show:1) Based on the APSIM model, the absolute error RMSE between measured values and simulated values of spring wheat in seedling stage, mature stage and yield is lower, the relative error NRMSE is controlled within 10%, It shows that the precision of simulation is high. The "D" index is in the range of 0.49-1 and most sites close to 1, it shows that the measured values are in good agreement with the simulated values and simulation effect is apparent. The "MAE" index value is lower. The validation of the APSIM model is applicable to the growing areas of spring wheat in Inner Mongolia2) In the 50 years of 1961-2010, the temperature of Inner Mongolia such as average temperature, maximum temperature and mean minimum temperature were increased, the Eastern area had a largest increase,the Western area had a minimum value.The total precipitation had a reducing trend, the Eastern area had a largest reduction, the Western area had a minimum reduction, the total precipitation of the middle region had a increased trend. The evapotranspiration of total potential in the whole area was on the rise. most significantly in the Western region; the average solar radiation decreased, the rising trend of Western area was significant. The average solar radiation in the whole area showed a decreasing trend, the middle area showed a significant downward trend, the Eastern showed an upward trend.The average humidity has a decreased trend, the middle area and Western area were extremely significant.The average wind speed decreased in the West and East,and minimum trend was in the East.The soil surface temperature had a significantly rising trend.3) In the 50 years of 1961-2010, the change trend of yield of spring wheat in Inner Mongolia was increased at first and then decreased.The Western area increased at first and then decreased,the middle region was gradually decreased, the Eastern area had a fluctuation trend.The Western area had a maximum yield in three regions in recent 50years,the middle area had a minimum value,The yield distribution from the middle to the East and West was gradually increased.4) Air temperature and soil surface temperature were the main meteorological factor affecting the growth period of spring wheat in Inner Mongolia,and the average maximum temperature influence was greater than the average minimum temperature during the growing period of Spring Wheat, followed by the relative humidity and solar radiation, and the most insensitive meteorological factors was precipitation, wind speed and evapotranspiration of spring wheat in the growth period. The growing period of spring wheat with changes of air temperature and soil surface temperature showed a negative correlation in East and West.5) Temperature, solar radiation and air humidity were major meteorological factors that affecting the yield of spring wheat in East and West of Inner Mongolia, and the average minimum temperature influence was greater than the average maximum temperature. Wind speed, precipitation and potential evapotranspiration effects on yield was small.6) The growing period of spring wheat in Eastern and Western was positively correlated with temperature factors, In the recent 50 years, with the increase of temperature, the growing period was shortened. The yield of spring wheat in Eastern was positively correlated with temperature factors and solar radiation, with the increase of temperature, the yield in eastern was generally upward trend, the yield of spring wheat in East and Middle was negatively correlated with temperature factors, with the increase of temperature in recent 50 years, spring wheat yield generally presented a downward trend in West and Middle.