Chinese scientists have developed a technology which can
effectively curb the deterioration in the rich black earth farmland
in the country’s northeastern region.
The technology is important for it can help preserve the status of
northeastern region as China's largest granary and prevent the
black earth belt from disappearing.
A
similar five-year research program was recently completed by a
group of experts with the
Heilongjiang Agricultural Modernization Research Institute,
affiliated with the Chinese
Academy of Sciences.
Program head Meng Kai said that the researchers have discovered
that the imbalance between nutrient and moisture content of the
black earth in the Heilongjiang and soil erosion constitute the
main hindrances to growth of crops in different types of black
earth.
Meng said that the crescent-shaped black earth belt, covering parts
of northeastern Heilongjiang and Jilin
provinces, is the most fertile land in China.
At
present, more than 7 million hectares of the 10-million- hectare
black earth belt have been developed into the largest commodity
grain production base of the country, the grain output from which
accounts for more than 60 percent of the two provinces' total.
Compared with the other two black earth belts in the United States
and Ukraine, the black earth belt in northeastern China was
developed earlier.
Lack of protection in the past has resulted in the disparity
between crop-growing and conservation of the black earth. In
addition, serious soil erosion has occurred and the organic matter
in the black earth has dropped by more than 50 percent.
Still worse, the black earth layer is 0.3 to 1 centimeters thinner
on average than the original 30 to 100 centimeters.
Experts said that the black earth layer might disappear within 50
years if action is not taken now, especially as the drop in soil
fertility has led to the reduction of grain output by 30
percent.
Chinese researchers found that factors that curb the growth of
crops are different in varying thickness of the black earth. Such
factors are lack of nutrients and moisture for crops in the middle
and late growth stages, adverse changes of soil structure and
decline of nutrition, and lack of bioactivity.
To
overcome the obstacles to the crop growing on the black soil, the
researchers adopted mechanical, chemical and biological
technologies to improve the physical structure of the soil and
adjust the make-up of nutrients to raise the fertility of the black
earth.
As
a result of the measures, the per hectare grain output rose by more
than 10 percent, totaling over 420 kilometers; the use ratio of
fertilizer and moisture all went up by 10 percent, respectively;
and the organic matter in the soil began to rise.
Sources from the Ministry of Agriculture said that effective
protection of the black earth in northeast China will play a key
role in China's goal of achieving an extra 140 million tons of
grain by 2030.
(Xinhua News
Agency 09/27/2001)