BEIJING, Aug. 27 (Xinhua) -- Chinese scientists are
warning that the country's northeast breadbasket regions are in danger of losing
their fertility because of soil erosion and degeneration.
"The northeast areas are the granary of the country.
Soil erosion and degeneration will jeopardize the nation's grain security," said
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 part of Inner Mongolian Autonomous Region,
covers more than 35 million hectares. It is one of the three largest black soil
areas in the world, along with similar land masses in Ukraine and the United
States.
Studies by the Northeast Institute of Geography and
Agro-ecology under the CAS and the Heilongjiang provincial soil retention
research institute show the thickness of the soil has dropped dramatically from
more than 80 centimeters to less than 30 centimeters in the last 60 years.
The density of organic substances in the soil has
fallen from 12 percent in the 1940s to less than 2 percent, experts said,
adding that about 85 percent of the soil is lacking sufficient 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. Its yields feed 10 percent of the country's population.
However, excessive farming, overuse of fertilizers
and relentless logging have caused erosion and degeneration of the soil quality.
Soil erosion has adversely affected local ecology,
resulting in more frequent droughts, floods and sandstorms, said Yan Baixing, a
researcher with the Northeast Institute of Geography and Agro-ecology.
The Heilongjiang Province has suffered spring
droughts for 10 consecutive years. Soil became dust, blew away and became
sediment in rivers and lakes, raising the river beds and increasing flood risks
in the rainy season, Yan said.
"We need do everything to protect the soil from
erosion and degeneration now. If we don't take action now, history will be
repeated," Zhang said.
Zhang referred to the "dust bowl" disasters which hit
the United States in the 1930s, caused by decades of extensive farming that
promoted erosion coupled with severe drought. The soils amassed in dark clouds,
blackening sky and forcing the exodus of millions at the time.
"We can't kill the goose that lays the eggs. The land
must not be farmed in a destructive way," said Zhang.
Last week, China's National Development and Reform
Commission (NDRC) issued a plan aimed to rejuvenate the northeastern provinces.
Protection of the black soil is an important part of their 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 the irrigation
facilities, and do everything we can to transform the low-yield crop fields into
high-fertility land," said Zhang Guobao, NDRC Vice Minister, at a press
conference.
Researchers said more ponds and reservoirs need to be
built to restore soil moisture, and forest belts need to be in place to
stabilize the soil. They are also encouraging farmers to leave manure and corn
stalks in the field to increase nutrient content.
More than 100 million tons of natural fertilizers
like manure and corn stalks are produced every year in northeast China, Zhang
Xudong said. If used effectively, they could enrich about 5 million hectares of
low-yields cropland in five to 10 years, he added.
