By Brian Hefty

The simple answer is YES, spring soil testing is fine.  However, it’s not quite that simple.

Fall soil tests equal spring soil tests if you test late in the fall, your ground then freezes rock hard immediately after that, and in the spring you test as the ground is unthawing.  If you are in an area with a mild winter or if you test early in the fall or late in the spring, your fall vs. spring results could vary significantly.  For example, you may get a bunch of rain in between which could leach out nitrate, sulfate, and boron.  On the other hand, you could get more organic matter mineralization; and if you don’t have a crop (or weeds) growing over the winter, your soil test levels could actually rise in the spring compared to fall.

What we typically advise you to do is pull your soil tests at the same time of year each time you sample.  That way you have taken out one of the variables, meaning you should get a more accurate read on whether or not your fertility levels are truly rising or falling over time.

Personally, I would prefer to see you test in the fall.  That way you can apply fall fertilizer more accurately.  That also gives you all winter to better analyze and scrutinize your soil tests.

All that said, it’s springtime now (or at least will be soon), so if you still need to test, we encourage you to get it done.  The number one question we had all winter was, “How can I cut my expenses in 2015?”  Let’s face it, it’s fun to save 10 cents on Roundup, but Roundup costs a grand total of $4 or less per acre.  When you invest $100 or more per acre in fertilizer, where do you think the big savings will come from?

If you don’t know how to read a soil test, here’s our best advice for you today:

  1. Go to agphdsoiltest.com today.  Set up your fields, and at least take one or two of those fields and soil sample them this spring.
  2. Pull your own soil tests in those fields using the free Ag PhD Soil Test app for your smartphone.  This allows you to grid sample your own fields quickly and easily.  If you only sample a couple of fields, it should take no more than a couple hours to pull all the tests and send them to the lab.
  3. You will get your sample results within a week.  When you do, thoroughly look through the tests and talk to a Hefty agronomist or directly to Darren and me on Ag PhD Radio (844-442-4743).  In addition to getting the soil lab’s recommendations, you will get our recommendations for free as part of the Ag PhD Soil Test program.
  4. Once you have your soil test results, you can use the program to make variable rate fertilizer application maps and controller files that can be downloaded and used in your equipment.

TAKE ACTION!  Here is my number one message for you today.  Don’t just do what you’ve always done.  At least soil sample one or two fields on your farm.  Get the results.  Look at the recommendations.  Learn what these things mean.  I am almost positive that your fertilizer dollars could be better spent, at least in areas on your farm.  Is it possible that taking $10 out of your nitrogen budget and investing that in potassium, phosphorus, sulfur, or micronutrients could pay?  Is it possible you are just flat-out over-fertilizing?  Is it possible that across the board you are under-fertilizing?  You don’t know, and I don’t know unless you pull some soil tests and get a complete analysis of those samples.  Isn’t it worth a couple hours and a few dollars to find out?