国内精品一区二区三区最新_不卡一区二区在线_另类重口100页在线播放_精品中文字幕一区在线

Scientists are worried that China’s northeastern fertile regions are in danger of suffering from irreparable damage due to soil erosion and degeneration.

 

"The northeast areas are the granary of the country. Soil erosion and degeneration will jeopardize the nation's grain security," warned Zhang Xudong, a soil expert with the Shenyang-based Institute of Applied Ecology under the Chinese Academy of Sciences (CAS).

 

 

China's expanse of black soil, spanning Heilongjiang, Liaoning and Jilin provinces and entering the Inner Mongolia Autonomous Region, covers more than 35 million hectares. Along with its sister sites in Ukraine and the US, it is one of the three largest black soil areas in the world.

 

Studies by the CAS’ Northeast Institute of Geography and Agro-ecology and the Heilongjiang provincial soil retention research institute show an alarming drop in soil thickness in 60 years, falling from 80cm to under 30cm.

 

A further worry comes from the drop in the density of organic substances in the soil, from 12 percent in the 1940s to less than 2 percent, experts said, which translates into 85 percent of the soil suffering from insufficient nutrients.

 

The crescent-shaped black soil belt is a leading commodity grain base in China, accounting for 30 percent of the country's total grain output, feeding 10 percent of the population.

 

However, excessive farming, overuse of fertilizers and relentless logging have caused the soil to erode and its quality to degenerate.

 

Soil erosion has adversely affected the local ecology, resulting in more frequent droughts, floods and sandstorms, said Yan Baixing, a researcher with the Northeast Institute of Geography and Agro-ecology.

 

Heilongjiang Province has been assailed by spring droughts for a decade. Soil turns to dust, blew away and settles as sediments in rivers and lakes, causing levels to rise and increasing flood risks during the rainy seasons, Yan said.

 

Zhang said: "We need to do everything to protect the soil from erosion and degeneration now. If we don't take action now, history will be repeated".

 

Zhang is referring to the "dust bowl" disasters which hit the United States in the 1930s, caused by extensive over-farming which led to erosion and drought. Soil amassed in dark clouds, blackening the sky and forcing the exodus of millions at the time.

 

"We mustn't kill the goose that laid golden eggs. The land must not be farmed to death," Zhang said.

 

Last week, China's National Development and Reform Commission (NDRC) issued a plan that will try to rejuvenate the flagging northeast. Protection of the black soil is an important part of the agenda.

 

"Protecting the soil doesn't mean we have to cut more trees to develop arable land. What we need to do is to reinforce irrigation facilities, and do everything we can to transform the low-yield crop fields into high-fertility land," Zhang Guobao, NDRC vice-minister, said at a press conference.

 

Researchers said more ponds and reservoirs would help restore soil moisture, and stable forest belts would rebalance the soil. Furthermore, farmers are being encouraged to leave manure and corn stalks in the field to increase nutrient content.

 

(Xinhua News Agency August 28, 2007)