Installment 3

Why is it important spend time selecting a good soil lab and then use the same lab year after year?


 Soil labs can be very individual in their methods, types of tests used, and their approach to soil testing and interpretation.  They often differ significantly in cost per sample tested.  They may give a very brief interpretation of your results or a very detailed one.  They also have some things in common.  Most of them have certain test methods that they recommend on certain types of soil.  They often have specialized knowledge of the soils and crops in their normal service area. They should have the experience and knowledge to perform the type of tests and provide you with the relevant interpretation needed to provide you with a useful result.  That’s the reason they’re in business!

It will definitely pay off to do some research and talk to the lab you intend to use about their reasons for testing your soil a certain way.  This is especially important when you are just getting started testing or thinking about increasing the number or frequency of your testing.  To get the maximum benefit from a soil test, growers need to have enough confidence in their test results to take some action based on the results.  A good place to start evaluating a lab is to read through their philosophy and a summary of the lab’s methods.  The more labs you get familiar with, the easier it becomes to evaluate them.  It is very useful to ask other growers about their opinions and recommendations.  We advise that you talk to 2 or 3 labs before you settle on a choice because we recommend…


Using the Same Soil Lab Year after Year

Again, soil labs are highly individualized in the way they treat and test samples.  If you send the same soil sample to different labs you may get substantially different results (and/or interpretations!).  Although comparing the results of the same sample from two labs can give you some interesting information, it may also be about as useful to your farm as comparing apples and oranges.  It is more useful to track the changes in the soil from year to year with tests sampled the same way and analyzed by the same lab.  In that way you can analyze trends in soil condition as well as the year to year “snapshots”.

Your ultimate decision on the type of soil test taken and which lab to use should depend on the cost of the test, it’s usefulness based on your soil type and crop selection, and your level of confidence in the lab being considered.

Note: It is important to remember that the results of a soil sample can only be helpful if a proper taken sample is submitted to the lab.  Each lab should have it’s preferred method of taking and transporting the sample.


Considerations for Choosing a Lab –  Recap:

Labs vary on their standard testing parameters and the type of tests they use for each one.

Some labs are more willing to spend time with customers.

Costs for testing can vary significantly from lab to lab.

Level of interpretation may differ greatly from lab to lab.


Next up

Understanding terms used on a soil test


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