Creating the first such law in the nation, on January 1, 2005 the Minnesota legislature made it illegal to use fertilizer containing the nutrient phosphorus (P) on residential lawns. The law does not apply to newly seeded lawns (same season); golf courses who employ a trained professional applicator; or lawns that show phosphorus deficiency by means of a soil test.
The law — which also makes illegal the application of fertilizer to impervious surfaces like streets, sidewalks, and driveways — is administered by the MN Department of Agriculture. It is enforced by local units of government as a petty misdemeanor, but perhaps more significantly the law draws attention to the over-enrichment of lakes and rivers through overuse and careless use of fertilizer. Native soils in the Metro are naturally rich in phosphorus, so the Minnesota Department of Agriculture recommends a soil test if an existing lawn is failing to thrive.
University of Minnesota Soil Testing Laboratory: soiltest.cfans.umn.edu/
Minnesota Department of Agriculture water quality protection information: www.mda.state.mn.us/protecting/waterprotection/phoslaw.htm