The Ohio Phosphorus (P) Risk Index is used to calculate the risk of losing phosphorus from farm fields by looking at multiple variables such as soil type and water flow. Due to increased attention being paid to water quality in recent years, this index has also been getting a lot of attention. The question, however, is how accurate is the index?

 
Dr. Elizabeth Dayton with The Ohio State University (OSU) has been working toward an answer to that question since she began her edge-of-field research project, On Field Ohio, in 2012 after receiving a significant farmer investment from the Ohio Corn Marketing Program, Ohio Small Grains Marketing Program and the Ohio Soybean Council.

 
“With increased concern about water quality throughout the country, agriculture has constantly been targeted,” said John Linder, chairman of the Ohio Corn Marketing Program. “A robust functioning P Risk Index will help us reduce the risk of runoff and protect water quality without sacrificing productivity.”

 
The goal of On Field Ohio is to update and revise the Ohio P Risk Index so it more accurately reflects the risk of runoff through the evaluation of transport (surface runoff, erosion, subsurface flow) and source factors (soil, fertilizer, manure). The more accurate the risk calculation, the more accurate farmers can be when making nutrient management decisions for every individual field.

 
“On Field Ohio will bring value back to our farmers by making the P Risk Index more accurate and precise,” said Patrick Knouff, OSC chairman from Shelby County. “This effort is unprecedented and has caught the attention of a lot of people not only in Ohio, but in other states as well.”

 
Soon after the corn, soybean and wheat organizations made their commitment, other top Ohio agricultural organizations came on board. In total, Ohio agriculture has provided over $1 million toward this effort. That funding was matched in 2013 when it received a matching $1 million grant from the U.S. Department of Agriculture.

 
The project is currently in its third year. Data is being collected throughout the state with a total of thirty fields monitored in the Upper Scioto, Upper Wabash, Grand Lake St. Mary, and Western Lake Erie Basin watersheds. In addition to revising the index, the project will promote the new version to Ohio farmers.

 
“No farmer wants to lose nutrients,” said John Hoffman, chairman of the Ohio Small Grains Marketing Program. “Updating the Ohio P Risk Index will help identify issues and provide guidelines for keeping nutrients on the fields.”