DEPARTMENT OF AGRICULTURE AND RURAL DEVELOPMENT  
PESTICIDE AND PLANT PEST MANAGEMENT DIVISION  
REGULATION NO. 634. COMMERCIAL FERTILIZERS  
Filed with the secretary of state on March 7, 2022  
These rules take effect 7 days after filing with the secretary of state.  
By authority conferred on the director of the department of agriculture and rural  
development by section 8516 of the natural resources and environmental protection act,  
1994 PA 451, MCL 324.8516)  
R 285.634.1, R 285.634. 3, and R 285.634.7 of the Michigan Administrative Code are  
amended, and R 285.634.2 is rescinded, as follows:  
R 285.634.1 Fertilizers for agricultural crop production; specialty fertilizers.  
micronutrient content.  
Rule 1. Plant nutrients in addition to nitrogen, phosphorus, and potassium when  
mentioned in any form or manner must be guaranteed. Guarantees must be made on the  
elemental basis. Sources of the elements guaranteed, and proof of availability must be  
provided to the director upon request. Except guarantees for those water-soluble nutrients  
labeled for hydroponic or continuous liquid feed programs, and guarantees for potting soils  
and lawn soils, the minimum percentages that will be accepted for registration or licensing,  
or both, are as follows:  
Element  
Percent  
1.0000  
0.5000  
1.0000  
0.0200  
0.1000  
0.0005  
0.0500  
0.1000  
0.0500  
0.0005  
0.1000  
0.0500  
Calcium (Ca)  
Magnesium (Mg)  
Sulfur (S)  
Boron (B)  
Chlorine (Cl)  
Cobalt (Co)  
Copper (Cu)  
Iron (Fe)  
Manganese (Mn)  
Molybdenum (Mo)  
Sodium (Na)  
Zinc (Zn)  
R 285.634.2 Rescinded.  
R 285.634.3 Placement of micronutrient guarantees on label.  
October 13, 2021  
2
Rule 3. Only the guarantees or claims for the plant nutrients listed in R 285.634.1 will be  
accepted. Proposed labels and directions for the use of the fertilizer must be furnished with  
the application for license or registration, or both, upon request. Any of the elements listed  
in R 285.634.1 that are guaranteed must appear in the order listed and must immediately  
follow guarantees for the primary nutrients of nitrogen, phosphorus, and potassium, if  
present.  
R 285.634.7 Tonnage reporting.  
Rule 7. Tonnage reports and fee payment must be on a form provided by the director of  
the department must be for the annual period of January 1 to December 31. The reports  
must cover all fertilizers, soil conditioners, and peat products sold for application in this  
state.  
December 15, 2021  
;