Taking a Soil Sample for Testing Step by Step

Following up on my previous post about testing for soil fertility: For those who don’t know how to take a soil sample, it’s real easy. Here’s a step-by-step walk-through with photos.

The process: Tale a shovel, small trowel or just a spoon and collect a soil sample, send it off with your payment to the soil laboratory you select, and in a few weeks, you’ll get your results. If you don’t have an “official” box, that’s fine. Just use any clean container. For example, I used a box that held cans of catfood.

To obtain a soil sample for testing, take a shovel or implement of some kind and put small amounts of soil in a clean box. Make sure it's not covered in turf grass; but only an inch or so below the roots, so the sample includes only topsoil, not subsoil. (Photo by Jim Ewing)

To obtain a soil sample for testing, take a shovel or implement of some kind and put small amounts of soil in a clean box. Make sure it’s not covered in turf grass; but only an inch or so below the roots, so the sample includes only topsoil, not subsoil. (Photo by Jim Ewing)

Go around your garden and take a small amount and put it in the box. Dig below the rootline; you don’t want grass or turf or weeds in it; but just an inch or so deep, so you are getting topsoil and not the harder, more compact subsoil.
Go to another area and do the same.

Once you have put a few spades of soil from various places in the garden, mix them up, so the soil is uniform; pick out any rocks or grass or other debris. (Photo by Jim Ewing)

Once you have put a few spades of soil from various places in the garden, mix them up, so the soil is uniform; pick out any rocks or grass or other debris. (Photo by Jim Ewing)

Crumble it all up and mix it up and either take it to your local extension service office or send it off. Most states have a testing facility, usually affiliated with a university, university cooperative extension service, or a state department of agriculture or natural resources.

In Mississippi, the Mississippi State University Cooperative Extension Service Soil Testing Laboratory analyzes soil. It only costs $6 for a routine analysis. For additional information, see http://msucares.com/crops/soils/testing.html, visit your local county extension service office or write: Soil Testing Laboratory, Box 9610, Mississippi State MS 39762; or call (662) 325-3313.

Land grant universities nationally are dropping soil testing programs. So, if you are reading this in a state where it is no longer available, here is a list of commonly used private labs compiled by Colorado State University: http://www.ext.colostate.edu/pubs/crops/00520.html

Collecting a soil sample is required annually for certified organic growers; but if you’re not organic, it’s still a good idea to see what’s going on with your soil. As stated in my earlier blog, when I first started sending off samples in Lena, because we lived in a terrain with red clay and sandy soils basically only good for growing pine trees, the tests came back showing high acid in the soil, in the 5.0 range.

Over several years, amending the soil with tons of composted horse manure and growing cover crops year round to build up vegetative matter (called “green manure”) and balance out the acid soil, we managed to bring the soil to a neutral level: 6.6 pH. That was a huge success.

Additionally, by digging a soil sample each year before you plant, you also get a good idea of how your topsoil is doing. Each year, your topsoil should be thicker, the consistency of the soil showing better tilth, and the fertility of the soil greater. If it’s not, then you should address that with more soil amendments and crop rotation.

You want to add humus and composted material to hold moisture and build tilth, increase fertility and provide optimum conditions for microbial life.

Jim PathFinder Ewing is a journalist, author, and former organic farmer now teaching natural, sustainable and organic agricultural practices. His latest book is Conscious Food: Sustainable Growing, Spiritual Eating (Findhorn Press). Find Jim on Facebook, follow him @EdiblePrayers or @OrganicWriter or visit blueskywaters.com.

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One response to “Taking a Soil Sample for Testing Step by Step

  1. We have an extension center about 25 miles away from me. I wanted to get my soil tested for harmful nematodes, but was too lazy to do so. Luckily, I’m not sure that they were an issue, or that I had them at all, but I’d still like to get my soil tested for pH. Thanks for the post on something a lot of us don’t think about as frequently as we probably should!

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