Minnesota Long-Term Phosphorus Management Trials: Phase 1 – The Build Period


Start Date: 2010

Principal Investigator: Albert Sims

Organization: University of Minnesota, Southern, Southwest, and Northwest Research and Outreach Centers

Status: Complete

Background Information:

Phosphorus (P) management in Minnesota is based on one of two philosophical approaches: Build and Maintain (B&M) or Sufficiency. Some agriculturalist believe that higher fertilizer applications associated with the B&M approach is necessary to obtain and maintain the high production levels in today’s agricultural systems. In most cases, there is little evidence to support this belief, but seldom do experiments examine the two approaches in side-by-side tests.


This research set out to answer the following: Is the maximum yield potential greater or similar in the B&M approach, in which there is little, if any, economic return for annual fertilizer applications, compared to the Sufficiency approach, in which there is generally an economic return for annual fertilizer applications?

Key Findings:

Phase I, results indicate that in most of the cases, the plots achieve the desired extractable soil P levels for each STP category, depending on the soil P extractant evaluated suggested for Minnesota soils. The Morris site is the only one that has lower extractable P values for each category, but we still have to include the soil test P values for 2014 to get a final conclusion for this site. In general, results indicated that for most of the sites, we met the goals proposed on Phase I related to the establishment of the four soil test P categories.

©2017 Agricultural Fertilizer Research and Education Council of Minnesota