Influence of climate change on sowing time of winter wheat in Shaanxi Province

Characteristics and variation of temperature and sowing time for winter wheat were analyzed on the basis of the weather data and survey data of winter wheat.It was found that the annual average temperature increased significantly in the past 21 years and the most obvious increasing occurred in winter.The average temperature of ten days during sowing dates of winter wheat(mid September to early October) increased by 0.1 to 2.0℃,available accumulative temperature above 0℃ before winter also increased significantly,over-wintering period shortened by 3 to 14 days,The suitable sowing for winter wheat is gradually postponed.The conclusion was that the appropriate sowing time for winter wheat could be postpone about 5 days than current state for the sustainable climate warming trend.