中国耕地食物生产变迁及“非粮化”影响评估

Changes of Cultivated Land Food Production in China and the Impact Assessment of“Non-grain”Use

研究目的:揭示1978年以来中国耕地食物生产变化规律,量化“非粮化”对耕地食物生产变化的影响程度,为“非粮化”治理、保障食物安全提供基础依据。研究方法:食物热量计算模型、LMDI分解法。研究结果:(1)经过波动增长(1978-1998年)、波动减少(1998-2003年)、快速回升(2003-2016年)和缓慢增长(2016-2020年),2020年中国耕地食物热量达113.23×10^(14) kJ,是1978年的2.58倍。(2)耕地食物生产结构呈现口粮减少而蔬果、油料、玉米快速增长的特征,其中口粮热量占比下降了近20个百分点,且西北、广西和青海的耕地食物热量主体分别由口粮转为玉米、糖料和油料;蔬果生产增速最快,热量占比增加了5.02倍。(3)1978-1998年和1998-2003年耕地食物热量变化主要由口粮引起,影响程度分别为46.31%和-64.84%;2003-2016年和2016-2020年耕地食物热量增加分别源于玉米和蔬果的贡献,程度为53.42%和28.30%。(4)1978-1998年、1998-2003年和2016-2020年,“非粮化”分别在14.63%、73.30%和23.81%的程度上抑制了耕地食物热量增长,其中,2016-2020年,“非粮化”是上海、江西、海南和贵州耕地食物热量减少的主因。研究结论:中国耕地食物生产在总量增长的同时向多样化转型,“非粮化”抑制了耕地食物供给增长。要树立大食物观,以耕地食物增产作为分区域、分次序推进“非粮化”治理的重要原则,重点关注“非粮化”导致耕地食物供给减少的地区。

The purposes of this study are to reveal the change law of food production in concerning cultivated land in China since 1978,and to quantify the degree of influence of“non-grain”use on the change of cultivated land food production,to provide theoretical basis for the governance of“non-grain”use and food security.The research methods include food calorie calculation and LMDI models.The results show that:1)experiencing fluctuation increase(1978-1998),fluctuation decrease(1998-2003),rapid recovery(2003-2016)and slow growth(2016-2020),the food calories of cultivated land in China reached 113.23×10^(14) kJ in 2020,2.58 times that of 1978.2)The food production structure of cultivated land in China is characterized by the decrease of grain and the rapid increase of vegetables,fruits,oil crops and corns.Grain ration was the main body of food calories in cultivated land,but the proportion of calories decreased by nearly 20 percent.The production of fruits and vegetables grew the fastest,with the proportion of calories increased by 5.02 times.3)The changes of food calories in cultivated land during 1978-1998 and 1998-2003 were mainly caused by ration,with the influence degrees of 46.31%and-64.84%,respectively.From 2003 to 2016 and from 2016 to 2020,the contribution of corn and vegetables and fruits accounted for 53.42%and 28.30%,respectively.4)From 1978 to 1998,1998 to 2003 and 2016 to 2020,“non-grain”use inhibited the increase of food calories of cultivated land by 14.63%,73.30%and 23.81%,respectively.In 2016 to 2020“,non-grain”use was the main reason for the decrease of food calories of cultivated land in Shanghai,Jiangxi,Hainan and Guizhou.In conclusion,while the total amount of cultivated land food production increased in China,the cultivated land food production changed to diversification,and the“non-grain”use restrained the increase of cultivated land food supply.It is necessary to set up the concept of big food,take the increase of cultivated land food production as an important principle to promote the“non-grain”use control by region and order,and pay attention to the areas where the“non-grain”leads to the decrease of food calories in cultivated land.