Why must the red line of 1.8 billion mu of arable land be upheld?

In 2006, the Outline of the Eleventh Five-Year Plan for National Economic and Social Development, adopted by the Fourth Session of the Tenth National People's Congress, explicitly stated that 1.8 billion mu of arable land was a binding target for the next five years and an impassable red line.

1.8 billion mu was calculated on the basis of five sets of data: First, the amount of arable land. After investigation and calculation, the National Land Administration Bureau concluded that the net amount of arable land was 1.97 billion mu. Second, the population figure. According to predictions by authoritative departments, by 2040 or 2050, the population peak will be 1.5 billion to 1.6 billion. By then there will be more than 1 billion urban residents and about 500 million rural residents. Third, the amount of urban and rural construction land. At that time, urban and rural construction land totaled 380 million mu. Referring to the actual occupation levels of developed countries such as the United States and Japan at the time, and based on the ratio of arable to non-arable land in newly occupied land for urban and rural construction in the preceding years, by 2040 urban and rural construction would still occupy more than 200 million mu of arable land. In addition, more than 100 million mu of arable land would be reduced through returning farmland to other uses, disaster damage, and other causes. Fourth, the amount of reserve arable land resources. Nationwide, the resources suitable for developing into arable land, including farmland consolidation and remediation of abandoned land, at the very most total more than 200 million mu. Offsetting the increases and decreases in the third and fourth sets of data, by 2040 it will be possible to retain 1.8 billion mu of arable land. Fifth, the figure for grain demand. At the per capita consumption level of moderately developed countries, and referring to the daily per capita food energy requirement (moderate requirement) proposed by the World Food and Agriculture Organization, each person needs 500 kg of grain per year, and 1.5 billion people need 750 billion kg. However, China's total grain output has long hovered at 500 billion kg. If land quality and the level of agricultural science and technology can be improved, then over more than 50 years it is possible to increase grain output by 250 billion kg. It can thus be seen that 1.8 billion mu is truly the lower limit of the arable land China must retain now and in the future. The red line of 1.8 billion mu must never be broken. It is both a high-voltage line for protecting arable land and a warning line for food security, and it must be strictly guarded.