Research on the Variation of Water Suitability of Winter Wheat——with Tianshui City as an example
PU Jin-yong et al (Lanzhou Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climatic Changing and Reducing Disaster of Gansu Province,Key Open Laboratory of Arid Climate Change and Reducing Disaster, Lanzhou,Gansu 730020)
[Objective]The study was to explore the influence of rainfall on the winter wheat growth and development and yield. [Method] Based on growth characteristics of winter wheat and its water utilization and the phonological observation data from 1981 to 2006 in Tianshui agrometeorological experiment station, a model of water suitability degree that could estimate the water suitability was set up to analyze the water suitability during winter wheat growth in Tianshui city. [Result] The water suitability model could objectively reflect the dynamic change of water suitability of winter wheat and its relationship with yield. From 1981 to 2006, the water suitability degree in growing stage before winter was increased obviously at the speed of 0.02/10a and was decreased gradually year by year at the speed of 0.01/10a in overwinter stage. [Conclusion] The water suitability of winter wheat was best during the overwinter and jointing stage and worst during the growing flourishing stage.