New legislation aims to protect Michigan’s waters from phosphorous in turf fertilizers

New legislation prohibits the use of phosphorus fertilizers on residential or commercial lawns, beginning January 1, 2012.

One of the primary contaminants of surface water in Michigan is phosphorus, much of which comes from non-agricultural application such as turf fertilizers. Phosphorus is readily accepted as a critical component for plant growth and is a common component of fertilizers used by homeowners. According to  Kevin Frank with MSU’s Department of Crop and Soil Sciences, phosphorus movement from urban landscapes can be attributed to several sources including the physical movement of soil or organic debris (tree leaves, grass clippings, animal waste), the leaching or runoff of phosphorus from the soil, and direct movement of phosphorus from fertilizer that is applied to impervious surfaces. Phosphorus movement that is not attributed to a specific activity or land use is often attributed to home lawn applications. Excess phosphorus in lakes and rivers can cause a number of problems including increased algae growth and fish kills.

In the agricultural sector, soil tests have become standard practice in determining the need for different formulation and amounts of fertilizers, and new legislation (Michigan Fertilizer Law 1994 PA 451, Part 85, Fertilizers) aims to encourage the same conservative approach in homeowner fertilizer applications. In Minnesota and Wisconsin, similar regulations have been passed and the results are visible in the many fertilizer formulations we find in the store which no longer include a phosphorus component. This is a major environmental advance with seemingly few drawbacks, particularly for Michigan where we have phosphorus-rich soils that rarely require supplemental applications.

According to the Michigan Department of Agriculture and Rural Development (MDARD), the legislation prohibits the use of phosphorus fertilizers on residential or commercial lawns beginning January 1, 2012. Phosphorus applications for agriculture or for new turf establishment, applications based on soil test results, certain types of manure, and golf courses that complete an approved training course are not prohibited by the new legislation. The only circumstances that allow for the application of fertilizers with available phosphorus are: if a tissue, soil or other test performed within the preceding three years indicates that the level of available phosphate in the soil is deficient to support healthy turf grass growth or establishment (order a soil test kit from the MSU Extension Bookstore); if new turf is being established using seed or sod; if the product is a finished biosolid, an organic manure or a manipulated manure and it is applied to turf at a rate of not more than 0.25 pounds of phosphorus per 1,000 square feet at any one time; if a golf course has successfully completed a training program approved by the MDARD.

Fertilizer cannot be applied to frozen soil or soil saturated with water. Any fertilizer released onto an impervious surface must be cleaned up promptly. The other phosphorus provisions in Act 299 include new definitions, setbacks from surface water, $50 civil fines and outreach information. Community phosphorus fertilizer ordinances in existence before December 16, 2010, are grandfathered.

For more information on the new legislation or how you can help protect Michigan’s water resources, visit the MDARD webpage or

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