Subject: [Homestead] China ag disaster affects U.S. and world
Date: Sun, 19 Sep 2004 10:17:47 -0700
If China can't feed itself, it either resorts to a long-term uncertain
ability to be the factory-to-the-world to provide revenue to buy food,
or attack its neighbors whose soil and agricultural practices are less
damaged.
China's economic revolution is coming at a cost. While improved
prosperity and government incentives convinced millions of people to
give up the rural life and move into towns and cities, China's
agriculture is in rapid decline, prompting fears that the country that
is home to one-fifth of the world's population will soon be unable to
feed itself.
Those fears have been heightened by two new reports by Chinese
scientists. They reveal that a national push to encourage farmers to
abandon the millennia-old tradition of growing rice in favour of fruit
and vegetables is having a profound and detrimental affect on the
quality of China's soil and water.
After just five years, fields growing fruit and vegetables are becoming
more acidic and barren, while nitrogen and phosphorus levels and fungal
epidemics are rising sharply.
Since 1998, the area of land in China devoted to grain crops has fallen
by 15 per cent. In August, Beijing confirmed that grain yields have
fallen by a fifth in that time, and consumption in 2004 is expected to
exceed production by a record 37 million tonnes. This demand for
imported grain has triggered a 30 per cent rise in global grain prices
in 2004, and further rises are expected as Chinese demand soars.
The root problem is that China is urbanising fast. Already 500 million
Chinese live in towns and cities, and the government wants that to rise
to 800 million by 2020. Cities are spreading across former farmland and
are getting first call on scarce water resources.
They are also changing food markets: while prices for grains such as
wheat and rice are capped by the government, city people are willing to
pay high prices for fruit and vegetables. And the government is
encouraging millions of farmers to meet this soaring demand by
converting rice and wheat fields to growing these more profitable crops.
*More acidic*
As a result, in the past decade, farmers have converted 13 million
hectares, an area the size of England, to fruit and vegetables. It is
this unprecedented change that has triggered the new concern about
deteriorating soils.
Researchers from the government's Institute of Soil Science in Nanjing
have found that soils in fields converted to growing vegetables are
becoming dramatically more acid, with average pH falling from 6.3 to 5.4
in 10 years. Meanwhile nitrates in the soils are at four times previous
levels, and phosphate levels are up tenfold (/Environmental Geochemistry
and Health/, vol 26, p 97 and p 119).
The changes in soil chemistry have been accompanied by an equally
dramatic decline in soil bacteria and an epidemic of fungus. The
deterioration is worst when the crops are grown under plastic.
These changes are starting to hit vegetable yields and quality. "Some
plants show abnormal growth, deformed fruits and various plant diseases
which are not easy to control by the usual pesticides," says Cao Zhihong
of the Institute of Soil Science. There is, in addition, "wide concern
because of possible groundwater and well drinking water pollution by
leached nitrates and phosphates". Already, a third of well water exceeds
government norms for nitrate.
"Anything that disrupts microbial activity and function in soil could be
expected to affect long-term soil productivity, and have serious
consequences," says Rui Yin, a co-author of the studies.
Western agronomists suggest that changes in soil chemistry are not being
caused by growing fruit and vegetables, but by farmers applying too much
fertiliser to them. While China harvests a similar amount of the crops
to the US, it uses almost twice as much fertiliser, says Lester Brown,
president of the Earth Policy Institute in the US and an expert on
Chinese agriculture.