China province promotes conservational tillage to protect black soil

CHANGCHUN -- Authorities in Northeast China's Jilin province are promoting conservational tillage to protect black soil, one of the most suitable soils for growing crops.

Jinlin governor Jing Junhai has proposed in this year's government work report to increase the total area of conservational tillage to more than 1.2 million hectares from the current level of 667,000 hectares.

Straw mulching is a major method developed by Chinese agriculturalists to promote conservational tillage. It can effectively increase the fertility of black soil while reducing air pollution caused by straw burning.

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.

According to a national land survey, Jilin has 7 million hectares of black soil, accounting for 23.3 percent of the total black soil area in China. It is also a major grain producer, ranking the fifth among provincial-level regions in the country.

With a 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 the local environment and grain production.

The thickness of the soil dropped from 60 to 70 centimeters in the 1950s to 20 to 30 cm at present, said Liang Aizhen, a researcher on agriculture with the Chinese Academy of Sciences, adding that "it takes 200 to 400 years to form a 1-cm-thick humus layer in black soil."

In recent years, China has stepped up efforts in black soil conservation. In 2018, the country's first local regulation on black land conservation took effect in Jilin.

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