An APSIM Simulation And GIS Analysis Based Study On Yield Increase Potential And Its Spatial Variation Of The Wlieat-maize System

To define the wheat-maize yield increase potential and its geographical difference inthe Hebei plain, APSIM models were built base on soil data, meteorological data duringthe time period from1954to2011at7main sites, e crop growth data and yield data fromdemonstration and field experiments to simulate yield potential of the wheat-maizesystem in the7districts and to analyze its spatial variation among districts and historicaltrends in the past58years. Yield gap and yield increase potential of the wheat-maizesystem in various places in the Hebei Plain was calculated using the simulated potentialyield and statistical data. The geographical information system software ArcGIS was thenused to analyze geographical variation of yield and yield increase potentials of thewheat-maize system in the Hebei plain. The main results are as follows:1. Yield potential of winter wheat increases gradually from10556.7kg/ha in thenorthwest to11168.8kg/ha in the southeast in the Hebei plain, with the lowest valueappears in Shijiazhuang and the highest in Cangzhou, and the in-between values inHandan, Langfang, Hengshui and Xingtai. Yield potential of summer maize variesbetween15246.6kg/ha and17022.7kg/ha among different regions with the lowestpotential in Xingtai and the highest in Cangzhou.2. The yield increase potential of winter wheat varies between3072.3kg/ha to5109.6kg/ha in the Hebei plains among different areas, with the highest potential appearsin Cangzhou and the lowest in Baoding. The yield increase potential of summer maizevaries between5942.1kg/ha and8482.2kg/ha. Cangzhou has the highest yield increasepotential of maize while Shijiazhuang has the lowest yield increase potential of maize.3. Sunshine hours and annual average temperature are higher in the areas withhigher crop yield potential, while those areas with better infrastructure and facilities,especially irrigation infrastructure and facility and modern mechanical equipments, havehigher actual yields.With a relatively poorer irrigation infrastructure and facility in Handan, poorermechanical equipments in Hengshui and Langfang and poorer irrigation infrastructureand facility and mechanical equipments in Cangzhou, actual crop yields in these regionsare lower than those in area with better infrastructure, facilities and equipments, andhence leave a big potential for increasing yield by improving infrastructure, facilities andequipments for crop production. Under a condition of limited water resources, increasingwater delivery and water use efficiency, better institution and management in waterresource allocation and increasing farm size to adopt more advance equipments in crop production are the important ways to explore the existing yield increase potential of thewheat-maize system.4. In the past58years between1954to2011, annual average temperature in theHebei plain increased by2.38℃with an annual average higher temperature of0.041℃.Temperature rise in the most recent30years was accelerating and the annual averagetemperature increased0.052℃per year. Annual sunshine hours declined by279.1hourswhile annual precipitation decreased by39.04mm in58years. The impact of thesechanges on the wheat-maize yield potential and corresponding copping strategy remainthe issues for in-depth and systematic mechanism study.