Ohio scientists rewriting state’s phosphorus risk index
A soil scientist with Ohio State University's College of Food, Agricultural, and Environmental Sciences is in the midst of a three-year, $2 million project to keep more nutrients and water on farm fields as part of an effort to improve the state's water quality.
Researcher Elizabeth Dayton's On-Field Ohio project is designed to offer growers more options to reduce agricultural runoff in Ohio waters by revising the current U.S. Department of Agriculture-Natural Resources Conservation Service Ohio Phosphorus (P) Risk Index to better predict the risk of phosphorus moving off farm fields.
Her goal is to make the P index, which is now used in all nutrient management plans, more accurate by increasing management options for farmers to reduce phosphorus runoff; and to create a Web-based tool so farmers can easily calculate and manage their phosphorus runoff.
Because the Ohio P Risk Index is used by farmers statewide in developing nutrient management plans for both manure and commercial fertilizer application, it is important that the index be as accurate an indicator as possible, Dayton said.
"We know a lot, but we don't know how good is good, so taking a more comprehensive look at how each management practice works on a specific field under real-world conditions will allow us to better quantify how well those practices can work for growers statewide," she said. "The feedback we have received from the farming community is that they are ready, willing and eager to be a part of the solution."
The project is funded through a $1 million U.S. Department of Agriculture Conservation Innovation Grant and $1 million in matching donations from Ohio agriculture groups.
The project involves setting up water sampling equipment on 32 sites across Ohio farms that grow wheat, corn and soybeans to sample surface and subsurface runoff to determine how much phosphorus is leaving the field, and how different soils and management practices affect the amount of phosphorus in runoff.
Phosphorus available to plants during a growing season, former management practices and soil physical properties are also being evaluated on each study site, Dayton said.
Already, the equipment installed on 24 sites has collected more than 2,000 water samples for testing since October, she said.
"To get to the root of the problem, you have to get to the source," Dayton said. "You can see that best at the edge of the field because that is where the offsite transport of nutrients and sediment occurs."
Or in other words, where runoff meets the waterways that lead to Ohio's rivers and lakes, including the Scioto River, Lake Erie and Grand Lake St. Marys.
Farmers are concerned about nutrient loss, believing that it is likely to have a negative impact on water quality and profit potential, said Greg LaBarge, an Ohio State University Extension field specialist and one of the leaders of Ohio State's Agronomic Crops Team. The team also includes scientists from the Ohio Agricultural Research and Development Center.
OSU Extension and OARDC are the outreach and research arms, respectively, of the college.
While phosphorus fertilizer is essential to Ohio crop production for food, fuel and fiber, farmers feel that they have a limited amount of control over nutrient loss on their farms and the impacts that those nutrients have on water quality, according to a 2013 survey conducted by Ohio State researchers.
But, the survey found, most farmers are willing to take at least one new action on their farm to reduce nutrient loss.
For Terry McClure, that's meant opening his farm to participate in the On-Field Ohio project. His 3,800-acre corn, soybean and wheat farm in Paulding County has several of the sampling equipment installed and tracking runoff from his farm.
The 5thgeneration farmer said he wanted to be a part of the project because "if you might be a part of the problem, then you should want to be part of the solution."
"Since the Dust Bowl, farmers have been looking for solutions anytime something happens that impacts their farms and their operations," McClure said. "Even though farmers are using less and less phosphorus on their farms, the issue of water quality is ongoing.
"So while we don't know what is causing the issue in Ohio, agriculture needs to be one of the first to know and to better understand what we can do to change it. If we are losing nutrients from our fields then we need to make changes so our farms can continue to benefit."