Novice Gardening: Oops, I forgot to do a soil test
Those new to gardening, or starting a garden in a new place, are often advised to get their soil tested. Somehow, during decades of gardening, I never got around to getting a soil test. I won't try to talk readers out of testing soil because the results might be useful to some or at least interesting. In extreme conditions, or if there are continuing unexplained crop failures, testing might be necessary. Under ordinary conditions it's apparently not critical, because I've had lots of success without ever having one done.
My aversion to testing may be a result of doing lots of it in college. For my senior project I measured organic matter content by weighing soil samples before and after burning them in an extremely hot oven. I dissolved, and centrifuged and decanted. I shot tiny beams of light through extracts to ascertain levels of chemicals. Though results of my experiments were inconclusive, I did learn a few things, most importantly that I don't like lab work. It was all too abstract for me, and since leaving college I've indulged my interest in soil by actively building it and growing things in it.
Why did soil testing come to be considered necessary in the first place? Our forebears here in Appalachia were feeding their families from gardens long before testing became widely available. The fashion of testing soil for home gardening might have migrated from the practice of testing in industrial crop farming, where it's crucial to identify and correct deficiencies. Such farming takes place in relatively lifeless soils and testing allows growers to calculate precisely the chemicals needed for success. Quantifying the absolute minimum amount of inputs necessary keeps costs as low as possible.
Have you ever read on a seed packet to plant the seeds in rows three apart? This advice was written with the assumption that home gardeners will run a tiller between the rows on a regular basis to keep weeds down, another industrial farming practice. Some backyard gardeners replicate such practices, but many don't, and there's no need for the same level of precision when adding amendments. My home garden doesn't much resemble a row-cropped field. It's a heavily mulched spot, with many types of organic matter in various stages of decomposition. I'm confident that my plants’ needs for nutrients are being well served and most of the time I can tell by simply observing the plants whether they are happy and healthy.
A major reason I've eschewed testing is I'm pretty sure of what I would do about any deficiencies—add organic matter. It's a cure-all for just about everything and in fact is the basis of my entire gardening system. As it breaks down it adds nutrients, improves drainage and water retention both, and buffers soil pH, bringing it closer to neutral. All the soil inadequacies that might be revealed by a test can be improved by using compost and mulch.
I've admitted I'm no expert on tests, but I know that most tests accessed through the extension service or conservation district measure nutrients, pH, organic matter content, and the like. Even if there are no major deficiencies, a pH that is too high or low can mean that nutrients aren't available to plants. Bringing the pH closer to neutral is therefore important. A test will also measure the cation exchange capacity of soil. CEC is a fancy name for how many ions the soil is able to hold, and is meaningful because there are several important nutrients with a positive charge. Having negatively charged clay and organic matter components in the soil means these nutrients stick around and are available when needed. This is why I never complain about my clay soil, and just keep happily adding organic matter.
One thing these tests don't indicate is the presence of toxic chemicals, which is what I am most interested in finding out. My garden is part of an old farm that was historically in pasture and corn, and I'm curious about what chemical residues remain. Such testing is probably much more expensive than extension service testing, and I haven't taken this step yet. If you can get a free or cheap basic soil test, then you have little to lose. Just be aware that you don't necessarily have to follow the recommendations that will come along with the results. Advice to add lime, commercial fertilizers, or other amendments that must be bought is sure to accompany your results. Two decades of successful gardening tells me that such purchases are unnecessary. My garden isn't a lab or a lifeless field, but rather a complex ecosystem that is thriving because I feed it organic matter on a regular basis. I plan to carry on indefinitely, without a test. Whether you decide to have a soil test done or not, I hope this post has been illuminating. (The photo below was taken April 1, 2022.)