CERTIFIED LABS
The following member labs have met the certification qualifications of ALTA as of August 2025.
The Agricultural Laboratory Testing Association (ALTA) strives to ensure that member labs always provide their clients with accurate, reliable and consistent data. This is accomplished through lab participation in the ALTA-Lab Accreditation Program (LAP), which utilizes soil analyses data developed through the Agricultural Laboratory Proficiency (ALP) Program or North American Proficiency Testing (NAPT) Program, international testing programs. Members submit data to the ALTA-LAP program and it is evaluated every four months.
Labs must meet certain qualification standards each cycle to remain certified. The rules of certification may be found by clicking on the “Soil Certification” section on this site’s header bar.
CERTIFIED LABS - JULY 2025
Fort Wayne, IN
Fort Wayne, IN
Fort Wayne, IN
pH Salt 1:2
P-Mehlich 3 ICP
K-Mehlich 3 ICP
------------------------
pH Water 1:1
Sikora Buffer pH
SMP Buffer pH
Bray-P1
K-Ammonium Acetate
SOM-LOI
M3 Zinc
Harrington, DE
Fort Wayne, IN
Fort Wayne, IN
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
-----------------------
SOM-LOI
M3 Zinc
Bonduel, WI
Fort Wayne, IN
Ellsworth, IA
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
-----------------------
Bray-P1
Sikora Buffer pH
K-Ammonium Acetate
SOM-LOI
Zinc DTPA
M3 Zinc
Ellsworth, IA
Fort Wayne, IN
Ellsworth, IA
pH Water 1:1
P-Mehlich 3 Spec
K-Mehlich 3 ICP
-----------------------
P-Mehlich 3 ICP
Bray-P1
Sikora Buffer pH
K-Ammonium Acetate
SOM-LOI
Lincoln, NE
New Bremen, OH
Stratford, WI
pH Water 1:1
P-Mehlich 3 ICP
K-Ammonium Acetate
-------------------------------
Bray-P1
Sikora Buffer pH
Zinc DTPA
Stratford, WI
New Bremen, OH
Stratford, WI
pH Water 1:1
Bray-P1
K-Ammonium Acetate
-------------------------------
K-Mehlich 3 ICP
Sikora Buffer pH
SOM-LOI
Zinc DTPA
M3 Zinc
Lakewood, IL
New Bremen, OH
New Bremen, OH
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
New Bremen, OH
New Bremen, OH
New Bremen, OH
pH Water 1:1
Sikor Buffer pH
P-Mehlich 3 ICP
K-Mehlich 3 ICP
SOI-LOI
Charter Soil Testing - Dwight, IL
Charter Soil Testing - Dwight, IL
Charter Soil Testing - Dwight, IL
pH Water 1:1
P-Mehlich 3 Spec
K-Mehlich 3 ICP
-----------------------
Bray-P1
Fresno, CA
Charter Soil Testing - Dwight, IL
Charter Soil Testing - Dwight, IL
pH Saturated Paste
Bray-P1
K Ammonium Acetate
-----------------------
SOM-LOI
Zinc DTPA
Soil Nitrate
Centralia, IL
Charter Soil Testing - Dwight, IL
Milford Center, OH
pH Water 1:1
P-Mehlich 3 ICP*
K-Mehlich 3 ICP*
------------------------
SOM-LOI
Milford Center, OH
Charter Soil Testing - Dwight, IL
Milford Center, OH
pH Water 1:1*
P-Mehlich 3 ICP
K-Mehlich 3 ICP
------------------------
SOM-LOI
Shelbyville, IL
Shelbyville, IL
Shelbyville, IL
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
------------------------
Sikora Buffer pH
SOM-LOI
M3 Zinc
Omaha, NE
Shelbyville, IL
Shelbyville, IL
pH Water 1:1
Bray-P1
P-Mehlich 3 Color
K-Ammonium Acetate
Windsor, IL
Shelbyville, IL
Waterrown, WI
pH Water 1:1
P-Mehlich 3 Spec
K-Mehlich 3 ICP*
Waterrown, WI
Shelbyville, IL
Waterrown, WI
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
-----------------------
Sikora Buffer pH
SOM-LOI
M3 Zinc
Washington Court, OH
Washington Court, OH
Washington Court, OH
pH Water 1:1
P-Mehlich 3 ICP
K-Melich 3 ICP
-----------------------
pH Salt 1:2
Sikora Buffer pH
Bray-P1
K-Ammonium Acetate
M3 Zinc
Indianapolis, IN
Washington Court, OH
Washington Court, OH
pH Salt 1:2
P-Mehlich 3 ICP
K-Mehlich 3 ICP
-----------------------
SOM-LOI
Fairbury, IL
Washington Court, OH
Fairbury, IL
pH Water 1:1
Sikor Buffer pH
P-Mehlich 3 ICP
K-Mehlich 3 ICP
SOM-LOI
Zinc DTPA
Kearney, NE
Washington Court, OH
Fairbury, IL
pH Water 1:1
P-Mehlich 3 ICP
K-Ammonium Acetate
------------------------------
Bray-P1
pH Salt 1:2
Sikora Buffer pH
SOM-LOI
DTPA Zinc
Owensboro, KY
Memphis, TN - Champaign, IL Atlantic, IA
Memphis, TN - Champaign, IL Atlantic, IA
pH Water 1:1
Sikora Buffer pH
P-Mehlich 3 ICP
K-Mehlich 3 ICP
SOM-LOI
Memphis, TN - Champaign, IL Atlantic, IA
Memphis, TN - Champaign, IL Atlantic, IA
Memphis, TN - Champaign, IL Atlantic, IA
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
Shafter, CA
Memphis, TN - Champaign, IL Atlantic, IA
Shafter, CA
pH Saturated Paste*
PO4 Olsen*
K-Ammonium Acetate*
DTPA Zinc
