Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, February 24, 1995 TAG: 9502240084
SECTION: NATIONAL/INTERNATIONAL PAGE: A3 EDITION: METRO
SOURCE: ASSOCIATED PRES
DATELINE: WASHINGTON LENGTH: Medium
Soil erosion is washing away the world's ability to feed itself, with more than 1 billion people malnourished because of farmland lost to wind and water, researchers say.
Millions of tons of farm soil are being swept into oceans, rivers and lakes each year. Because of that erosion and population growth, per capita food production is falling rapidly and the picture will get even grimmer in the next century, David Pimentel of Cornell University said Thursday.
It takes about 1.2 acres of land a year to feed a varied diet to one person, but there's only about 0.6 acre per person worldwide available for farming now, said Pimentel. In 40 years, the farmland will be down to 0.34 acres per person, if present trends continue, he said.
It doesn't have to be that way, said the agricultural scientist.
``We know what to do to control erosion, but we aren't doing it,'' he said. ``Few people really appreciate the seriousness of the problem.''
In a worldwide study to be published today in the journal Science, Pimentel and his associates at Cornell found that erosion is destroying about 29 million acres of farmland a year. About 3.7 billion acres worldwide still can grow crops.
``In many regions, limited land is a major cause of food shortages and undernutrition,'' said Pimentel. He estimates that about 20 percent of the world's population of more than 5 billion already are poorly nourished.
Erosion, he said, is hardly recognized by most people because its effects are subtle. A single rainstorm on bare ground can strip away a millimeter (.03 inch) of soil, he said.
``If you look at the land, you wouldn't even notice the loss,'' said Pimentel. ``But that amounts to tons of topsoil lost per acre. It's insidious. Eventually, it catches up with you.''
The effect is cumulative. In 1776, for instance, the average U.S. topsoil was 9 inches deep. The average soil now is 5.9 inches deep.
``That's not going to be replaced,'' said Pimentel. ``It takes nature more than 200 years to form just 1 inch of topsoil and we're losing it about 17 times faster than its being replaced.''
Such measures as crop rotation and contour planting have controlled erosion and increased yields in experiments on damaged lands in Texas, Missouri and Illinois, the study shows.
by CNB