Soil erosion could devastate food sector
according to a new Cornell University study.
Valuable earth is being swept and washed away 10 to 40 times faster than it is being replenished, adding to the growing body of scientific evidence that environmental change is having a direct negative effect on the food sector.
"Soil erosion is second only to population growth as the biggest environmental problem the world faces," said David Pimentel, professor of ecology at Cornell.
"Yet, the problem, which is growing ever more critical, is being ignored because who gets excited about dirt?"
But this issue is increasingly gaining exposure. Pioneering Scottish research into the demineralisation of earth has strengthened the case that unless vital nutrients and elements are placed back into the soil, the quality of food will deteriorate.
The SEER (Sustainable Ecological Earth Regeneration) Centre's work builds on the work of Dr David Thomas, a primary healthcare practitioner and independent researcher, who recently made a comparison of government tables published in 1940, and again in 2002.
"Why is it that you have to eat four carrots to get the same amount of magnesium as you would have done in 1940?" he asked.
It would appear therefore that while the amount of arable land is shrinking dramatically, the quality of what is left is also receding.
"Erosion is one of those problems that nickels and dimes you to death: One rainstorm can wash away 1 mm of dirt," said Pimentel.
"It doesn't sound like much, but when you consider a hectare (2.5 acres), it would take 13 tons of topsoil - or 20 years if left to natural processes - to replace that loss."
The study, which pulled together statistics on soil erosion from more than 125 sources, also reports that the US is losing soil 10 times faster - and China and India are losing soil 30 to 40 times faster - than the natural replenishment rate.
The economic impact of soil erosion in the US alone costs about $37.6 billion each year in productivity losses. Damage from soil erosion worldwide is estimated to be $400 billion per year.
"Erosion is a slow and insidious process," said Pimentel. "Yet, controlling soil erosion is really quite simple: The soil can be protected with cover crops when the land is not being used to grow crops."
Pimentel's study on the food and environmental threat of soil erosion is published in a recent issue of the Journal of the Environment, Development and Sustainability (Vol. 8, 2006).
