Great time to do a soil test

 

Mulched garden bed

Sunday, December 6, 2020

 Late fall is a great time to do a soil test.  There is usually a spring rush on soil testing so doing one now gets you your results expeditiously and gives you plenty of time to decide how to improve your soil before spring planting.      

EYou can get a basic soil test done at your local cooperative extension office, sometimes for free or you can go for a more in depth soil test by mailing your soil out.  I am getting a local test done first.  I want to see what the basics look like (P-phosphorous, K-potassium, soil pH, calcium, magnesium, and zinc).  

You may be thinking, "What happened to N-nitrogen?".  Well, nitrogen is very volatile, it changes with temperatures and quickly over time so nitrogen isn't tested.  If you are adding compost or manure to your garden, you really don't need to add nitrogen fertilizer.  If you have more nitrogen than the plants can take up, it just runs off into streams and feeds the algae blooms that create dead zones and it costs money.

It is important to know what the pH of your soil is before you send off for an in-depth test as it changes which testing method is used.

The basic test is sufficient for getting a good harvest in the garden.  It is really all you need.  It is really smart to get a test because you can be adding fertilizer that is actually harming the growth and fruiting of your garden as well as causing contaminated run off into local streams and ponds.  In my area, we typically have sufficient phosphorous.  Too much phosphorous can cause plants to do poorly and even die.  Excess phosphorous run off has the same effect as nitrogen run off.  

How to take a soil test?  It is important to not include any mulch or compost that you may have added on top of your garden bed.  You want the actual soil.  It is best to take soil from the top 6-12" and from several spots in the garden bed.  You then mix the samples together and provide to your local extension office the amount they need to do the testing.  At our extension office, they need a cup of soil.

If you want to get a more in-depth test that includes more minerals and a reading on organic matter, you can send off to a soil lab.  For these tests, the sky is the limit on what you can have analyzed!

I had a more in-depth soil test done at Logan Labs in 2015 and then an individual analysis done at growabundant.com to get a more specific recommendation on improving mineral content of the soil.  After I get my local test done this month, I will send off for another in-depth test.  It's good to get testing done at the same lab, if possible, to monitor changes over the years.

If you are using organic fertilizers, these are slow release so adding to the garden early will make sure they are available when your spring garden gets going.  One more thing, make sure you keep your garden bed either growing something or covered for the winter to protect the soil you have worked hard to improve.

For more on improving minerals in your garden, and in your fruits and vegetables, The next step in garden production and your nutrition-soil minerals.