2018 Volume 31 Issue 3 Pages 152-165
The average temperature of the earth has increased about 1°C during the last 130 years (IPCC, 2007). Changes in crop calendars are also to be expected under climate change. This study revealed changes in crop calendars and the area of winter wheat cultivation, the main crop on the North China Plain. Furthermore, this study clarified the reasons for changes in terms of climatic variation and water policy. The combination of NDVIs by Pathfinder AVHRR Land (PAL) and SPOT/VEGETATION supported long-term analyses of 1982-2012. The greening season after winter dormant period has come faster with increasing spring temperatures. The sowing season has been delayed because of higher autumn mean temperatures and precipitation. Policies such as charging for groundwater withdrawal corresponding to water shortages and abolition of taxes promoting agriculture have influenced changes in winter wheat cultivation areas. Therefore, the winter wheat farming calendar and changes in crop cultivation area were investigated from a comprehensive perspective.
