基于合理膳食结构的2020-2050年我国食物用粮需求测算

测算我国未来粮食需求量是制定我国粮食安全相关政策措施的基础.目前我国城镇化水平加快，老龄化问题突出，完全二孩生育政策刚刚实施，正处于人口结构转型的关键期，而人口结构变动直接影响食物用粮需求.本文从满足居民营养健康标准的食物需求视角下，考虑人口年龄、性别和城乡结构，采用标准人消费系数法，测算了单独二孩政策、完全二孩政策和完全放开生育政策情景下2020-2050年我国食物用粮（包括口粮与饲料粮）的需求，并进行对比分析.结果表明：在完全二孩政策情景下，我国食物用粮需求将在2030年达到峰值39263.1万吨，比通常采用人均方法的计算结果低10061.0万吨；因城镇化率的提高将使2020、2030与2050年食物用粮需求分别增加约406.7万吨、1142.5万吨与1553.8万吨；生育政策调整所带来的人口规模与结构变化并不是2020-2050年我国粮食安全的主要影响因素.建议积极引导和鼓励生育，在适当时间进一步完全放开生育；同时采取有效措施将粮食损耗与浪费降到最低.

Estimating China's food grains demand from 2020 to 2050 based on reasonable dietary pattern

The estimation of China's future food grains demand is an important reference for designing food security measures. In recent years, the urbanization level has been accelerated, the aging problem has been serious and the universal two-child policy has been just implemented, so China has been in a critical period of demographic transition. Furthermore, the changes of population size and structure have a direct impact on food grains demand. Based on China's recommended nutrient intake, considering the age structure, sex structure and urban and rural structure of population, the paper uses the standard person consumption coefficient method to estimate the food grains demand (which includes grain ration and feed grain) for 2020-2050 years in three fertility scenarios, which are two-child fertility policy for couples where either the husband or the wife is from a single-child family, universal two-child policy and the birth limit be canceled policy. The results show that:under the universal two-child policy, China's food grains demand will peak at 2030, about 392.631 million tons, which is 100.610 million tons lower than that calculated with the per capital method; with the rise of urbanization rate, the food grains will increase about 4.067 million tons, 11.425 million tons and 15.538 million tons in 2020, 2030 and 2050 respectively; the demographic transition for fertility policy adjustment is not the main impacting factor of China's food security during 2020 to 2050. It is suggested that effective measures should be taken to guide and encourage bearing and rearing better children, to cancel the birth limit in a proper time, and to minimize the loss and waste of food grains.