The 55-year course of grain production in China has undergone earth-shaking changes. The total grain output increased from 1 132 billion Jin in 1949 to 5 123 billion Jin in 1998, an increase of 3.53% compared with 1949. Then the total output decreased, and remained at 469.5 billion kg in 2004, still 3. 15 times higher than 1949. The sown area of grain fluctuated from 1.956 to 65438+1.10.00 billion hm2 to the maximum sown area10.40 billion hm2, and remained at1.200 million hm2 in most years. Grain yield increased continuously from 1949 1029kg/hm2, 1970 reached 20 12kg/hm2, 1982 and 1992 reached 3/kloc-0.

Figure1-6 The development trend of China's grain planting area, total output and unit yield in 55 years.

(quoted from the crop database of the Ministry of Agriculture).