Use labs certified by the Agricultural Laboratory Testing Association.

The Agricultural Laboratory Testing Association maintains a list of privately owned commercial labs. The site lists the contact information, services provided and certification programs. Illinois Indiana Sea Grant's Lawn to Lake website also provides a complete list of labs.

Several land-grant universities house a soil laboratory.

• University of Missouri Soil and Plant Testing Laboratory
• University of Wisconsin Soil and Forage Lab
• Kansas State University Soil Testing Lab
• University of Kentucky Soil Testing Laboratory
• University of Minnesota Soil Testing Laboratory