气候变化背景下中国主要粮食作物生长期界定的研究综述

聚焦于水稻、玉米和小麦3大粮食作物，就生长期的定义、界定方法以及应用等方面对文献进行了梳理与归纳；基于局地、区域尺度视角，描述了我国不同品种、不同地区对生长期界定所存在的差异；对应用于气候变化背景下生长期的变化规律和气候变化特征这2方面的相关研究进行了综述．结果表明:作物生长期的起止日期主要依据界限温度或现实经验进行界定，界限温度是作物生长发育过程中的一个重要气候指标，我国主要以0、5或10 ℃为阈值；采用滑动平均方法准确估算作物播种和收获的具体日期，适用于局地尺度范围内生长期起止日期的界定．参考我国农业种植制度和粮食生产的实际情况，选定某时段作为生长期，便于开展区域尺度范围内气候因素的长期演变研究；改进作物生长期的界定，可准确分析区域农业气候资源变化；为气候变化研究的指标选取和参数优化提供依据，并有助于农业种植制度的制定、作物品种的布局优化等相关工作，能更好地保障作物产量并提高作物的生产潜力． 

Definition of growing period for major grain crops in China: a review

Growing period is an important indicator of growth and development of crops and utilization of agricultural climate resources．The start and end times and total period length are important in guiding agricultural production and in coping with climate change．The three major grain crops of rice, maize and wheat are examined．Variations in growing period definition for different crops and in different regions in China are described．Applications of growing period definition to growing period variation and characteristics of climate change during growing period are reviewed．The start and end dates of growing period are defined mainly according to critical temperature or practical experience．Critical temperature is an important climatic indicator in crop growth and development．Temperatures of 0, 5 or 10 °C are used as main thresholds to accurately estimate specific dates of planting and harvesting by the moving average method in China．It is suitable for the definition of starting and ending dates of growing period on local scale．Agricultural practices and the actual situation of grain production in China are also used to directly select the growing period．It is convenient to carry out long-term evolution of climatic factors on regional scale. Improved definition of growing period could better determine growing period of crops, and are helpful for the accurate analysis of regional climate changes, helpful also for the selection of indicators and parameter optimization in climate change research．This also facilitates the formulation of agricultural planting systems and optimization of crop variety layout, ensures crop yields, improves production potential of crops．