Beijing - The central government is encouraging provincial governments to do more to ensure there is enough arable land within their borders to feed the increasing numbers of people who live there.

Starting in September, the government will use a round of inspections to determine how well arable land is being conserved in China. It will look at the country's 31 provincial, municipal and autonomous region governments, the Ministry of Land and Resources said on its website on July 29.

The inspections are meant to gauge how well local authorities have done in the past five years at conserving the arable land in their jurisdictions, at guaranteeing a sufficient supply of farmland and at returning land to cultivation at times when they had allowed separate tracts of arable land to be put to different purposes, according to the ministry's announcement.

The results of the investigations will be consulted by the central government when it assesses whether officials have performed their duties.

The inspections are part of a government campaign to protect farmland from misuse. It comes in response to the recent rapid expansion of Chinese cities, which has occurred at the expense of attempts to conserve arable land.

The Organization Department of the Communist Party of China (CPC) Central Committee and other four central government departments will also participate in the check.

Lu Bu, a researcher at the Chinese Academy of Agricultural Sciences, told China Daily on Wednesday that this is the first time the Organization Department of the CPC Central Committee has participated in inspections to ascertain whether arable land is being conserved.

"It is obvious that the central government is now determined to crack down on illegal land use practices," he said.

In the period of its 12th Five-Year Plan (2011-2015), China has pledged to protect its 121.2 million hectares of available farmland and to otherwise do more to improve the quality of that land, the Ministry of Land and Resources said in July.

Meanwhile, the demand for construction sites in the country has continued to rise at a time when less and less land is becoming available for that use. That, in turn, has made the temptation to use land illegally stronger.

China saw 30,000 instances of illegal land use in the first half of this year, up 8 percent from what the number had been in the same period in 2010, the ministry's statistics showed.

The cases concerned the misuse of 18,500 hectares, including 6,300 hectares of arable land, according to official figures.

Li Chang'an, a public policy professor at the Beijing-based University of International Business and Economics, called on the central government to do more to supervise land use.

"So far, the local officials who had been investigated and punished in connection with cases of illegal land use have almost all come from the lower ranks, being village or county heads or something similar," he said.

"We must now investigate whether provincial authorities have overlooked these cases."