Keeping phosphorus out of the Everglades

"It is a partnership that has worked," said Samira Daroub, a professor of soil and water science at the UF/IFAS Everglades Research and Education Center in Belle Glade. "It is one of the success stories in the area and also in the country."

This year, the agricultural area has seen a phosphorus reduction of 79 percent, with an average in past years of more than 50 percent. State law requires a 25 percent reduction. Monitoring by the South Florida Water Management District shows an average number of 94 parts per billion of phosphorus in the water -- substantially better than the 500 ppb in 1986.

"The story is much bigger than even this astounding result," said Jack Payne, senior vice president of agriculture and natural resources at UF/IFAS. "The marketplace won't always take care of places like the Everglades, and that's why the work of public land-grant university scientists is so important. It's science in the service of society."

The Florida Department of Agriculture and Consumer Services works with UF/IFAS researchers and personnel from the South Florida Water Management District to develop and adopt best management practices (BMPs) for different types of agricultural operations. The BMPs are designed to benefit water quality and water conservation, while maintaining or enhancing agricultural production.

In 2014, the total phosphorus load reduction was 63 percent, attesting to the success of the partnership between the Everglades Agricultural Area (EAA) growers, the South Florida Water Management District, and University of Florida personnel, said Daroub, who has worked since 2002 to help farmers with BMPs in reducing phosphorus. She added that they have taken a three-pronged approach: -- Soil testing before fertilizing to see how much fertilizer, if any, is necessary; -- Regulating when and how much water can be pumped off of the farms; -- And cleaning out sediment from the canals before farm water is released into a maze of waterways that lead into the Everglades.

Anyone farming in the EAA must obtain a permit to do so -- and they have to attend a BMP training workshop to get and maintain that permit. Daroub and researchers conduct the twice-a-year workshops for nearly 250 farmers, ranchers and their personnel, including U.S. Sugar Corporation, Florida Crystals and Sugar Growers Co-operative -- the three largest farming entities in the EAA.

Paul Allen is co-owner of R.C. Hatton Farms, Inc, which grows a variety of vegetables and sugar cane in Pahokee. He said the board of the South Florida Water Management District, environmentalists and the entire audience gave growers a standing ovation this month when the 79 percent reduction was announced and growers were honored for their efforts.

"It's something I'll never forget," said Allen, who was there with his son. "We're all really happy about it and really proud."

The UF/IFAS program also focuses on new and innovative best management research. Daroub and researchers are currently conducting a five-year paired farm study to evaluate the impact of floating aquatic vegetation on sediment properties and phosphorus loads from eight cooperating farms within the EAA.

"Controlling floating aquatic vegetation may help reduce phosphorus loads on certain farms by reducing the generation of highly mobile organic sediments," she said.

The Everglades is a 2 million acre wetland ecosystem that begins in Central Florida and empties into Florida Bay. In 1986, a widespread algal bloom infested one-fifth of Lake Okeechobee, creating a gunk-filled soupy mixture that was a direct result of fertilizers from the EAA. Tested water showed 500 parts per billion of phosphorus near farms in the area; decades of draining fertilizer-laden water into the Everglades was slowing destroying the famed River of Grass.