Developments to Watch
WILL THIS FERTILIZER MAKE CROPS GLOW--OR JUST GROW?
Some see Florida's chalky mountains of phosphogypsum as a hazardous-waste eyesore. University of Florida researchers see 600 million tons of cheap fertilizer. Phosphogypsum, a by-product of phosphate fertilizer production, contains minute amounts of radium-226, which can decay to radon gas. Environmental groups are trying to pressure the Environmental Protection Agency to place stricter limits on its use.
But a new University of Florida study may embolden the EPA to ease present restrictions. It showed a 25% increase in crop yield when phosphogypsum, which contains calcium and sulphur, was used on forage grasses. A three-year study found that radon levels remained normal even when phosphogypsum was applied in larger-than-necessary quantities. Another benefit: Sulphate in phosphogypsum can bind to aluminum in soil, preventing crops from absorbing the toxic metal. Similar studies are being conducted in the Philippines and are expected to begin in Brazil and Turkey.EDITED BY PETER COY