Title:
Unbalanced Fertilizer Use, in an Uneven World
Description: This is
a VOA Special English Agriculture Report.
See text below
Text:
This is the VOA Special English Agriculture Report.
Fertilizer use differs from country to country, and
from too little to too much. Nitrogen and phosphorus
can produce big crops. But they can also pollute
water and air.
A recent policy discussion in the journal Science
compared the nutrient balances of different
agriculture systems. Researchers compared the use of
fertilizer in three areas that grow maize as a major
grain: China, Kenya and the United States.
By two thousand five, they say, farms in northern
China produced about the same amount of corn per
hectare as farms in the American Midwest. But the
Chinese farmers used six times more nitrogen, and
produced almost twenty-three times more surplus
nitrogen.
Government policies can have an influence. For
example, as China sought food security, its policies
increased fertilizer use.
The researchers note that farmers in the Midwest
used too much fertilizer on their crops through the
nineteen seventies. But improved farming methods
later increased their yields and, at the same time,
made better use of chemical nitrogen fertilizer.
Farms in western Kenya use just over one-tenth as
much fertilizer as American farms. Corn harvests
remain small. The researchers say farming methods in
Sub-Saharan Africa need to improve or else poor
quality soil will increase rural poverty. More than
two hundred fifty million people do not get enough
nutrients from crops to stay healthy.
Nutrient balances in agriculture differ with
economic development. Farmers lack enough inputs to
maintain soil fertility in parts of many developing
countries, especially in Africa south of the Sahara.
But countries that are developed or growing quickly
often have unnecessary surpluses.
Ammonia gas released by fertilized cropland is a
cause of air pollution. The land can also release
nitrous oxide, a heat-trapping gas.
Nitrogen runoffs from farms can create large dead
zones, like those in the Gulf of Mexico. Algae
microorganisms in the water overpopulate because of
the surplus nitrogen. The algae take much of the
oxygen from the water. Fish and other organisms die.
Laurie Drinkwater at Cornell University in Ithaca,
New York, was an author of the report. Professor
Drinkwater says farmers need to think about ways to
solve some of the causes of nutrient loss from
agriculture. She says different countries need
different solutions based on location, environment,
climate and population needs.
And that's the VOA Special English Agriculture
Report.
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Hi. I
personally reviewed this video and found it appropriate for
the news section of English Global Group. This
is a Voice of America video which covers an interesting
topic in Special English. I would appreciate some feedback from both
students and teachers about this video. You can comment in
the window below using any of a number of different services
including Facebook, Yahoo, AOL, and Hotmail.
