NCPA - National Center for Policy Analysis

Solving The Problem Of U.S. Soil Erosion

November 11, 1999

In 1995, a Cornell University study estimated that soil erosion cost the U.S. $44 billion each year, and a 1998 textbook called American erosion "as severe as it was in the 1930s." These assessments, however, relied on models and small-scale studies that didn't directly measure erosion, says the author of a study that found erosion is a less serious problem than some thought.

  • Erosion rates have declined markedly since the 1930s in one of the best-studied agricultural watersheds, the Coon Creek Basin in southwestern Wisconsin -- claims the study in Science, based on surveying data dating back to the 1930s.
  • Measuring soil loss from fields that ends up as sediment in rivers and flood plains, Stanley W. Trimble of the University of California - Los Angeles, found "The rate of sedimentation has greatly slowed over the last 60 years so that it now about 5 percent of what it was in the 1930s."
  • That translates into 80,000 tons of sediment accumulation a year from 1975 through 1993, compared to 1.2 million tons per year during the 1920s and 1930s.

The Cornell economic estimate used calculations of soil erosion made before farmers had complied with the 1985 Food Security Act, which required them to develop soil-conservation plans, says a U.S. Department of Agriculture official. More recent figures suggest erosion has since dropped by close to 40 percent. Based on new numbers, two USDA researchers calculate that U.S. erosion in 1997 cost $29.7 billion.

Source: Richard Monastersky, "Erosion: Dustup over Muddy Waters," Science News, August 21, 1999.


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