CHANGCHUN - A regulation on black soil conservation will take effect on July 1 in Northeast China's Jilin Province.

The regulation specifies how to control soil loss, increase the density of organic matter, and preserve the moisture and fertility of the soil.

The regulation also sets June 25 as Jilin's black soil conservation day.

"The regulation fills a legislative blank and will strengthen the protection of black soil," said Yu Ping, a member of Commission for Legislative Affairs of the Standing Committee of Jilin Provincial People's Congress.

China's black soil, spanning Heilongjiang, Liaoning and Jilin provinces and part of Inner Mongolian autonomous region, is one of the three largest black soil areas in the world.

With high density of organic matter, black soil is very suitable for growing crops. However, long-term cultivation and overuse of fertilizers have caused degeneration of the soil, threatening local environment and grain production.

Studies show the thickness of the soil has dropped dramatically from more than 60 centimeters in 1950s to less than 30 cm.