Spatial Adaptabilities of Spring Maize to Variation of Climatic Conditions

Environmental conditions have important effects on maize (Zea mays L.) growth. To examine spatial variation in maize yield and aboveground biomass and to understand differences in the response of maize yield and aboveground biomass to climatic factors under various ecological conditions, we conducted experiments from 2007 to 2010 at 34 locations in seven provinces in the spring maize region of northern China between 35 degrees 11' N lat and 48 degrees 08' N lat. We used a most widely cultivated maize hybrid ZD958. The maize yield and aboveground biomass (presilking and postsilking) were found to be strongly influenced by locations. A nonlinear relationship existed between the maize yields and latitude. Maize yield was the greatest (12.19 Mg ha(-1)) at 39 degrees 08' N lat, and the corresponding presilking and postsilking aboveground biomass at this location were 143.41 and 215.35 g per plant, respectively. Variations in the harvest index (HI) and 1000-kernel weight were the main reasons for yield latitudinal trends. Among the climatic factors, air temperature had the best relationships with variations in maize yield, HI, and 1000-kernel weight. With latitudes increasing northward, presilking aboveground biomass affected by growth duration length and accumulated solar radiation increased significantly. The aboveground biomass of postsilking stage that was affected by the maximum temperature, daily mean temperature, and growing degree days decreased significantly with latitudes increasing northward. However, there were no significant changes of total aboveground biomass with latitudes increasing northward.