Wis. Admin. Code § ATCP 50.50
(2) Applying for certification. A laboratory operator may apply to the department for certification under sub. (1). An operator shall submit a separate application, on a form provided by the department, for each laboratory for which the operator seeks certification. The application shall include all of the following:
(d) The soil tests, test methods, and nitrogen estimation methods used by the laboratory. The laboratory shall be capable of performing the following tests according to methods prescribed by the University of Wisconsin-Extension in Nutrient Application Guidelines for Field, Vegetable, and Fruit Crops in Wisconsin, UWEX Publication A2809 (2012), and by the University of Wisconsin-Madison soil science department in Wisconsin Procedures for Soil Testing, Plant Analysis and Feed & Forage Analysis, Soil Fertility Series (October, 2013) and shall be capable of estimating nitrogen levels based on those tests:
5. Organic matter (OM).
Note: Copies of the Nutrient Application Guidelines for Field, Vegetable, and Fruit Crops in Wisconsin. UWEX Publication A2809 (2012) and the Wisconsin Procedures for Soil Testing, Plant Analysis and Feed & Forage Analysis, Soil Fertility Series (October, 2013) are on file at the department and legislative reference bureau. To obtain a copy of the A2809, see s. ATCP 50.04 (3) (f) 4. (note). Copies of the Wisconsin Procedures publication are available at the University of Wisconsin website at: https://uwlab.soils.wisc.edu/about-us/lab-procedures-and-methods/.
(g) Other relevant information required by the department.
Note: The soil testing laboratory certification form and the list of approved soil testing laboratories can be found at the following web address: https://datcp.wi.gov/Pages/Programs_Services/ATCP50.aspx.
(4) Nutrient recommendations. If a certified laboratory recommends nutrient applications to a landowner that exceed the amounts required to achieve applicable crop fertility levels recommended by the University of Wisconsin Extension in Nutrient Application Guidelines for Field, Vegetable and Fruit Crops in Wisconsin, UWEX publication A2809 (2012), the laboratory shall make those recommendations in writing and shall disclose all of the following in the same document:
(c) The following statement, clearly and conspicuously printed adjacent to the laboratory’s recommended nutrient applications:
IMPORTANT NOTICE
Our recommended nutrient applications exceed the amounts required to achieve applicable crop fertility levels recommended by the University of Wisconsin. The amounts required to achieve the UW’s recommended crop fertility levels are shown for comparison. Excessive nutrient applications may increase your costs, and may cause surface water and groundwater pollution. If you apply nutrients at the rates we recommend, you will not comply with state soil and water conservation standards. You may contact your county land conservation committee for more information.
Note: To obtain a copy of A2809, see s. ATCP 50.04 (3) (f) 4. (Note).
(5) Records. A certified soil testing laboratory shall keep records of all of the following for at least 4 years, and shall make those records available for inspection and copying by the department upon request:
(6) Laboratory evaluation.
(a) The department or its agent may review the performance of a soil testing laboratory certified under this section. The department or its agent may do any of the following as part of its review:
(7) Denying or withdrawing certification.
(a) The department may deny, suspend, revoke, or impose conditions on a certification under this section if the department finds that the laboratory has done any of the following:
(8) Manure testing laboratories. Manure nutrient values determined by laboratory analyses do not qualify under s. ATCP 50.04 (3) (dm) 2. unless the laboratory performing those analyses complies with all of the following:
(a) The laboratory participates in the manure analysis proficiency program administered by the Minnesota department of agriculture, or in an equivalent proficiency program administered by the University of Wisconsin soil analysis laboratory, and provides copies of proficiency reports to the department upon request.
Note: A manure testing laboratory may qualify under sub. (8), regardless of whether the laboratory is certified as a soil testing laboratory under sub. (1). A laboratory may contact the department, at the following address, for information on how to enroll in a manure analysis proficiency program under par. (a):
Wis. Department of Agriculture, Trade and Consumer Protection
Agricultural Resource Management Division
Nutrient Management Program
PO Box 8911
Madison, WI 53708-8911
(b) The laboratory is capable of performing all of the following manure analyses according to methods prescribed by the University of Wisconsin-Extension in Recommended Methods of Manure Analysis, UWEX publication A3769 (2003):
4. Total potassium expressed as K20.
Note: The University of Wisconsin-Extension publication, Recommended Methods of Manure Analysis, UWEX publication A3769 (2003), is on file with the department and legislative reference bureau. Copies may be obtained by visiting the UWEX website at: http://learningstore.uwex.edu.
History: CR 01-090: cr. Register September 2002 No. 561, eff. 10-1-02; CR 05-013: am. (2) (intro.), (b), (c), (d) 2., and (f), cr. (8) Register May 2007 No. 617, eff. 6-1-07; CR 08-075: am. (2) (d) (intro.) and (8) (c) Register April 2009 No. 640, eff. 5-1-09; CR 13-016: am. (2) (intro.), (d), (4) (intro.) Register February 2014 No. 698, eff. 5-1-14; CR 16-083: am. (2) (d) (intro.), (8) (c), cr. (9) Register January 2018 No. 745, eff. 2-1-18; CR 23-024: cr. (7) (c) Register May 2024 No. 821, eff. 6-1-24.