A nationwide team of agricultural scientists, including Michigan State University associate professor and Extension soil scientist Kurt Steinke, has launched a decision aid that provides an unbiased, science-based interpretation of soil-test phosphorus and potassium values for crop fertilization. 

The Fertilizer Recommendation Support Tool — referred to as FRST — represents a significant advancement in soil testing for phosphorus and potassium, according to the researchers.

Using data from across the U.S., the tool is designed to enhance nutrient management, with an eye toward potentially saving farmers millions of dollars annually and reducing excess nutrient losses to the environment.

The new web-based tool is the result of collaboration among more than 100 soil science and agronomic professionals representing nearly 50 universities, USDA and several nonprofit organizations.

Project leader Nathan Slaton, a soil science researcher at the University of Arkansas, said the FRST project has accomplished two important objectives to advance phosphorus and potassium management for crop production.

“The first objective was to develop a national database to archive soil-test correlation and calibration research, ensuring that research information that supports crop fertilization recommendations is not lost as scientists retire,” Slaton says.

“The second was to provide a tool that anyone can use to review the research results relevant to their specific crops, soils and geographic area to check their soil-test-based fertilizer recommendations.”

Until now, soil fertility faculty in each state worked independently, making it difficult for farmers to compare or assimilate multistate guidelines.

The decision tool is intended to improve the accuracy of nutrient recommendations through independent, scientifically developed nutrient management best practices that farmers can believe in and adopt.

Currently, FRST provides critical phosphorus and potassium soil-test values, indicating where there is no expected yield increase from phosphorus or potassium fertilizer application.

What’s next?

In the next phase of the project, the tool will provide research-based phosphorus- or potassium-rate-response information to assist farmers in selecting the minimum fertilizer rate expected to produce maximal crop yield.

The current version, FRST v1.0, includes data from nearly 2,500 phosphorus and potassium trials for 21 major agricultural crops, mostly corn and soybean. The tool includes a map of the U.S. that shows the location of phosphorus and potassium trials represented in the database.

The map can be used to identify where the need for additional research data is greatest.

The database was constructed from both historical and current research data and includes trials from 40 states. The team plans to expand to other crops, cropping systems and nutrients, such as sulfur.

Several key features of FRST include:

For more information about FRST and how it can transform nutrient management for farms and organizations, visit soiltestfrst.org and select “Tool.”