CERTIFIED LABS
The following member labs have met the certification qualifications of ALTA as of December 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 - DECEMBER 2025
Fort Wayne, IN
Fort Wayne, IN
Fort Wayne, IN
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
------------------------
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
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
M3 Zinc
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
SOM-LOI
Stratford, WI
New Bremen, OH
Stratford, WI
pH Water 1:1
Bray-P1
K-Ammonium Acetate
-------------------------------
K-Mehlich 3 ICP
P-Mehlich 3 ICP
Sikora Buffer pH
SOM-LOI
M3 Zinc
Lakewood, IL
New Bremen, OH
New Bremen, OH
pH Water 1:1
*P-Mehlich 3 ICP*
K-Mehlich 3 ICP
-------------------------------
SOM-LOI
New Bremen, OH
New Bremen, OH
New Bremen, OH
pH 1:1 Water
Mehlich 3 P ICP
Mehlich 3 K ICP
----------------------------
Olsen P / Bicarb
Ammonium Acetate K
SMP Buffer pH
SOM-LOI
Zinc DTPA
NO3-N
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
Walkley-Black OM
Fresno, CA
Charter Soil Testing - Dwight, IL
Charter Soil Testing - Dwight, IL
pH Saturated Paste
Bray-P1
K Ammonium Acetate
-----------------------------
SMP Buffer pH
Zinc DTPA
Centralia, IL
Charter Soil Testing - Dwight, IL
Milford Center, OH
pH Water 1:1
P-Mehlich 3 ICP
*K-Mehlich 3 ICP*
------------------------
M3 Zinc
Milford Center, OH
Charter Soil Testing - Dwight, IL
Milford Center, OH
pH Water 1:1
P-Mehlich 3 ICP
*K-Mehlich 3 ICP*
Athens, IL
Shelbyville, IL
Shelbyville, IL
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
------------------------
Sikora Buffer pH
SOM-LOI
M3 Zinc
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
Windsor, IL
pH Water 1:1
Bray-P1
P-Mehlich 3 Color
K-Ammonium Acetate
-------------------------------
Olsen P / Bicarb
P ICP Mehlich 3
Sikora Buffer pH
Woodruff Buffer pH
SOM-LOI
Zinc DTPA
NO3-N
Windsor, IL
Shelbyville, IL
Windsor, IL
*pH Water 1:1*
P-Mehlich 3 Spec
K-Mehlich 3 ICP
Waterrown, WI
Washington Court, OH
Washington Court, OH
pH Water 1:1
P-Mehlich 3 ICP
*K-Mehlich 3 ICP*
-----------------------
Bray P1
Sikora Buffer pH
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
SOM-LOI
M3 Zinc
Indianapolis, IN
Washington Court, OH
Indianapolis, IN
pH Salt 1:2
P-Mehlich 3 ICP
K-Mehlich 3 ICP
-----------------------
pH Water 1:1
SOM-LOI
Fairbury, IL
Washington Court, OH
Indianapolis, IN
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
----------------------
Sikora Buffer pH
SOM-LOI
Zinc DTPA
Kearney, NE
Owensboro, KY
Owensboro, KY
pH Water 1:1
P-Mehlich 3 ICP
K-Ammonium Acetate
------------------------------
Bray-P1
pH Salt 1:2
Sikora Buffer pH
SOM-LOI
Zinc DTPA
Owensboro, KY
Owensboro, KY
Owensboro, KY
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
------------------------------
K Ammonium Acetate
Sikora Buffer pH
Adams-Evans Buffer pH
Zinc DTPA
Atlantic, IA
Owensboro, KY
Champaign, IL
pH Water 1:1
*P-Mehlich 3 ICP*
K-Mehlich 3 ICP
-----------------------------
Ammonium Acetate K
Woodruff Buffer pH
SMP Buffer pH
SOM-LOI
Zinc DTPA
Champaign, IL
Owensboro, KY
Champaign, IL
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
--------------------------
Woodruff Buffer pH
SMP Buffer pH
SOM-LOI
Zinc DTPA
NO3-N
Memphis, TN
Memphis, TN
Memphis, TN
pH Water 1:1
P-Mehlich 3 ICP
K-Mehlich 3 ICP
----------------------------
PO4 P Olsen / Bicarb
K Ammonium Acetate
Woodruff Buffer pH
Adams-Evans Buffer pH
SMP Buffer pH
SOM-LOI
Zinc DTPA
NO3-N
Shafter, CA
Memphis, TN
Memphis, TN
pH Saturated Paste
PO4 Olsen
K-Ammonium Acetate
----------------------------
DTPA Zinc
