Soil Sample Testing

Thank you for your inquiry about Soil Testing. Unfortunately, Iowa State University is not taking samples any longer. However, we are working to find some alternative soil testing labs that might work for our clients. Below are forms for two private sector testing labs. We recommend that you contact the company and view their webpage with any questions before submitting samples. These are not companies that we have used before so we ask that you research what you think will work best for you. You are welcome to contact us with feedback to help us with suggestions in the future. Following that below is information from ISU including information on other Universities that offer soil testing. If you decide to submit samples to a lab and get results back that you need help interperting please feel free to contact us and we will get you in touch with a specialist that can help you.
Private sector labs in Iowa:

www.waypointanalytical.com/HomeOwners

www.agsourcelaboratories.com/lawn-garden-testing-services

click her for Solum Lab Soil Submittal Form
University Soil Lab Resources:

Publications regarding soil testing and fertilizer recommendations:

Here is a short list of other ISU lawn and garden publications that include fertilizer recommendations. That may relate to a homeowner’s particular situation.

Soil Testing for Acreages… row crops, small grains, hay, pasture, commercial horticulture
For these crops, clients should use soil testing labs that maintain certification through IDALS. Labs have to use specified testing procedures and prove reliability/consistency with test results. IDALS runs blind soil sample tests through these labs on a regular basis. This list can change a bit over time as labs may occasionally fail the blind tests, but can return to the list with successful testing with IDALS next check.   Go to: http://www.iowaagriculture.gov/feedandfertilizer.asp; on the right side of the web site click on “Certified Soil Testing Laboratories”.  FYI, also of interest on this website is the “Ag Limestone Quarry Certification Report” which provides ECCE values for those calculating lime applications using local limestone quarries.
 
Using “Certified Soil Testing Laboratories” is important so that soil test results from these labs can be interpreted based on extensive ISU research, and able to use the ISU publication PM-1688, “A General Guide for Crop Nutrient and Limestone Recommendations in Iowa” to interpret their soil test and make economically sound recommendations. https://store.extension.iastate.edu/Product/A-General-Guide-for-Crop-Nutrient-and-Limestone-Recommendations-in-IowaThis is a lengthy publication, but it might be helpful to any farmer (landlord, consultant, etc.) planning on soil testing their crop and pasture acres. And if a client is new to soil testing, another critical publication to provide is “Take a Good Soil Sample to Help Make Good Fertilization Decisions”: https://store.extension.iastate.edu/product/3915
 
Regarding “Certified Labs”, ISU Extension office staff suggests using labs from the certified soil testing labs list that offer the “Field-Moist” (or Wet) potassium (K) test since this test is preferred over the “Dry” K test (oven dried samples). This reduces the list of labs to two:

  • Solum, Ames, IA:  http://solum.ag/  To use Solum, the client must call the lab and create an on-line account. Then they will have access to sample submission forms and other information.
  • AgSource, Ellsworth, IA:  http://agsource.crinet.com/  AgSource has more than one testing lab in the mid-west, but the Ellsworth lab is the closest lab to northeast IA.

1.   AgSource Agronomy page https://www.agsourcelaboratories.com/agronomy-agricultural-services
3.   Basic sample submission sheet from AgSource, Ellsworth Testing Lab https://www.agsourcelaboratories.com/Portals/11/Ellsworth/Ellsworth%20Soil%20Multiple%20Sample%20form.pdf
Why use the “Field-Moist” K test versus the “Dry” K test?
1.   Dr. Mallarino’s explanation of the benefits of Field Moist testing K: http://www.agronext.iastate.edu/soilfertility/info/Mallarino_2013%20Moist%20K%20testing%20NCERA-13%20Workshop.pdf
2.   Solum Lab’s shorter explanation of Dr. Mallarino’s work and the benefit of Field Moist testing K: http://www.solum.ag/complete-soil-testing/field-moist-testing/
 
Questions Call Jeanene at 641-423-0844 or jblick@iastate.edu

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