China marked its 17th National Day of Land yesterday. The idea is to save on the use of land and keep the area of arable land no less than 120 million hectares at least by 2010.

With one-fifth of the world's population, the country has only 10 percent of the total area of arable land worldwide. What makes this situation even worse is the rapid decrease of farmland in the past two decades.

The national land use program in 1996 set a target of no less than 129.3 million hectares of arable land by the year 2000, but the total area was reduced to 128.2 million hectares.

Then another target was set to keep the figure at 128 million hectares by the year 2005. But the figure ended up 122 million hectares. The latest land survey, completed in October last year, showed the total area of farmland was less than 122 million hectares.

Now the per capita arable land is only 0.09 hectares, less than 40 percent of the world average. The contradiction between the ever decreasing arable land and the ever increasing population makes the preservation of arable land an issue of vital significance to the future food security of the country.

Experts say 120 million hectares is the amount of land we must keep for the basic food security of the population in the decades to come.

Even if we can successfully keep the arable land at 120 hectares in 20 years, we will have to increase the import of grain to make up the gap between supply and needs as our population will likely increase to nearly 1.5 billion by that time.

It will also be difficult to keep the current area of arable land from being eroded by development projects in the face of the great appetite for land use by local governments nationwide. Many have already used up quotas several years ahead of their land use program.

There are always local governments that defy the call of the central authorities not to illegally occupy arable land. The call seems to have fallen on deaf ears as to the importance of preserving existing farmland.

Severe penalties must be imposed upon local governments who illegally occupy farmland. A number of localities have been found to hoard land for speculation.

An investigation found that more than 260,000 hectares of land was taken from farmers by 2004, but was left idle. Some local governments increase their revenue by selling land.