The Dirt on Dirt: Testing Your Soil
Published Thursday, Oct 23, 2014
Since arable land in urban areas is so sparse and eroded, testing your soil illustrates what components of the soil need support. This knowledge will reveal what we, the gardeners, need to make the soil as nutrient rich as it can be without hurting the Earth in the process. Below are a few tests with minimal or no cost that one can use to determine the health of your soil. We’ll show you how to do the tests, the rest is up to you.
Squeeze Test (Free)
Soil is one of three different types: loamy, clayey, and sandy. Loamy soil is preferable because it retains moisture and nutrients well but does not stay soggy. Clay soil holds a lot of nutrients but it drains slowly. Sandy soil drains quickly but does not retain the nutrients necessary for healthy soil.
(sandy, loam, and clay soil)
1. Take a handful of moist soil from your garden and squeeze it.
2. If it holds its shape, poke it lightly. If it then crumbles that means you have loamy soil.
3. If it holds its shape but doesn’t crumble after poking it, that means you have clayey soil
4. If it falls apart as soon as you open your hand, that means you have sandy soil.
The Worm Test (Free)
This is probably the best and easiest way to find out how healthy your soil is. Those creepy-crawlers that you found in the soil are actually your friends and they are essential to assessing the health of the soil. To perform the worm test:
1.The soil should be moderately moist at about 55 degrees (Fahrenheit).
2. Dig a hole one foot across and one foot deep. Put the soil on a tarp or any surface.
3. Sift through the soil with your hands and save any worms you have found. Put the soil back in the hole.*(see article link at bottom of page)
If you have found at least 10 worms, then you are in good shape. If fewer than 10 worms were found, then you may not have enough organic matter in the soil to support the worms. It is also possible that the soil is too acidic or alkaline; which brings us to the next test.
The pH test will show you how acidic the soil is, which will also indicate how well your plants might grow. Knowing soil acidity will give you an idea as to how conducive your soil is to nutrients. On a scale out of 14, very acidic is zero and very alkaline is fourteen. Generally you want your earth to be about neutral or a little acidic. Plants grow best with a pH between 6 and 7.
You can find a pH test at any Home & Garden store in your area. (If you don’t want a soil test from the store, try a DIY soil test at which you can find out about at wikiHow.) It is most important to follow the directions on the test as closely as possible in order to get the best results. After you have the results, you can consult other gardeners as to how to keep your soil healthy by reducing the acidity/alkalinity if needed (some tips on how to do so can be found here).
With these tests you will be able to successfully tell what shape your soil is in and what kind of ground you have. With only a few more steps, you will be on your way to creating a garden that could feed an army. Really, during World War I the “victory gardens” campaign- basically a patriotic urban gardening mission- created over $1 billion worth of foodstuffs. So start your own “victory garden” today.
– Written by Dylan Jarrell, Volunteer