Minnesota Long-Term Phosphorus Trial: Phase II, Testing Yield Response and Potential
Study author(s): Albert Sims, Dan Kaiser, Carl Rosen, Jeff Strock, Jeff Vetsch, and Karina Fabrizzi
Years of study: 2011 – 2017
Location(s): Becker MN, Waseca MN, Rochester MN, Morris MN
Important: for the complete report, including all tables and figures, please download using the links to the right.
Phosphorus management is critical to reduce environmental risk while sustaining field productivity. Phosphorus (P) is an essential nutrient and the second most commonly applied nutrient in Minnesota agriculture. Phosphorus fertilizer management is based on one of two philosophical approaches, Build and Maintain (B&M) and Sufficiency (Olson et al., 1987). The B&M approach recommends P fertilizer quantities needed to build the soil test P (STP) to or near a critical level over a period of years. The critical level is that STP level where there is less than a 5% chance the crop will respond to additional fertilizer. Once the target STP level is reached, annual applications of P fertilizer based on P removal of previous crop are required to maintain that STP. These applications are frequently based on P removal in the previous crop.