FORT PIERCE, Fla. — Phosphorus from fertilizer run-off can cause algal blooms in Florida’s waterways, especially in the summer months. However, if a slow-release phosphorus fertilizer is available, leaching loss of phosphorus will be minimal and algal blooms will be much less than occur with traditional fertilizers.
Just in time, while the world’s supply of high-quality phosphates will soon reach depletion, the University of Florida has a new patent for development of environmentally-friendly phosphate fertilizer. The new source from which slow release phosphate fertilizers may be developed is called dolomite phosphate rock. It is a byproduct of traditional phosphate production processes that until now, had been low quality, according to documentation from UF’s Office of Technology and Licensing.
“Phosphate is the second nutrient after nitrogen widely used throughout the world to fertilize crops,” said Zhenli He, a soil and water science professor at UF’s Institute of Food and Agricultural Sciences Indian River Research and Education Center in Fort Pierce (IRREC). He said new fertilizer products produced with the dolomite phosphate rock would cost 30 to 50 percent less than do traditional fertilizers.
Zhenli He invented a novel method using naturally occurring organic materials to activate phosphorus in dolomite phosphate rock, thus boosting phosphorus available for crops. The patent is called, “Conversion of Low-Grade Phosphate Rock to Produce Slow-Release Fertilizer.” He estimates the newly developed products will cost 30 to 50 percent less in the commercial development phase.
“Phosphorous used in traditional fertilizers is produced by dissolving phosphate rock with sulfuric acid,” said He. “Producing slow release phosphorus fertilizers with low-grade dolomite phosphate rock, or DPR, does not require sulfuric acid or release harmful toxins into the environment.”
The fertilizing phosphates, he said, are released into the soil in a controlled manner—or slowly, with minimal leaching. He estimates the new dolomite sourced phosphorous will leach at least 80 to 90 percent less than do traditional phosphate products.
He said the activation process that blends the phosphate rock powder with organic molecular activating agents leaves behind no hazardous wastes.
The results of He’s studies are available in an international peer-reviewed publication, the Journal of Agricultural and Food Chemistry. Publication of additional findings is pending in two more scientific journals.
He said he appreciates funding provided by the Florida Institute of Phosphate Research for the laboratory and greenhouse tests that were completed. He is at this time seeking to fund field trials needed to advance the new phosphate production method to the point of commercialization.
“The method is now patent-protected and ready for testing in the field where the new phosphate fertilizer sources may be evaluated,” said He. “Development of the slow release fertilizers will depend on the commercialization processes—and that may take time.”
–Robin Koestoyo
UF|IFAS
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