1 引子我国是一个农业大国,现有耕地面积约4.7亿亩。据大丰收的1985年统计,粮食生产达9800亿斤,棉花8300万担,其他经济作物如油料、甜菜、烟叶、麻等共有1.6亿万斤。“民以食为天”,现在我国人均粮食只有800斤左右,到2000年我国人口将增长至12亿。那时,粮食的消费量要大大增加,需增产50％才能满足国民的需求. 1 Introduction China is a large agricultural country with an existing cultivated area of ​​about 470 million mu. According to the 1985 bumper harvest statistics, grain production reached 98 billion kilograms, while 83 million were cotton. Other cash crops such as oilseeds, beets, tobacco leaves and hemp reached a total of 160 million kilograms. “People live on their own’s food,” and now China’s per capita food is only about 800 kilos. By the year 2000, our population will grow to 1.2 billion. At that time, the consumption of food should be greatly increased, and it needs to increase production by 50% to meet the needs of the people.