Finding My Balance: Soil Test Results
I know, I know, I should have done a soil test a long time ago. And we did, but it was almost 8 years ago when my husband was leading all things garden related, and if he shared the results of the test, I’ve forgotten we ever had the conversation. But with nearly every Master Gardener course including the phrase “based on your soil test,” I knew it was time to see what kind of shape my soil is really in.
So I took my dozen samples of soil, mixed them up in a bucket, and sent my baggie of dirt off to a testing lab that had been recommended to me. The University of Minnesota Extension Service offers testing, but it didn’t offer as much information as I wanted – mostly just pH and the 6 top nutrients. With all the good information I’ve been learning from Garden Maker about micronutrient needs, I wanted to see as many of the essential nutrient levels as I could.
As far as the other results, here’s what we found out. There’s no loss of phos in our soil. The phosphorus level is “very high,” which surprised us until we remember how much chicken manure we put on the garden the first few years we lived here. Clearly, we need to back off the phosphorus in our fertilizer for a while! Our pH looks decent at 6.7, but we could use a little more organic matter in our sandy soil – we’re only at 2.53%. We’re full up on calcium (yay for my tomatoes!), but magnesium, sulfur, and potassium are low, so supplementation is in order.
I think what surprised me most was what wasn’t in my report. I knew from my Master Gardener class that there is an issue with testing for nitrogen that makes the results misleading or incomplete (but I’ll be darned if I can find my notes about why that is), so I wasn’t surprised to not see a nitrogen level or recommendation identified. But the trace minerals I specifically wanted to see were just quoted as a ppm (parts per million figure) without a “desired range,” so I still won’t know what to do until I do some more research. And although there was a nutrient recommendation, it only addressed the “big 6” nutrients and no suggestions were given about what kind of fertilizer or what ingredients to look for on a label.
So what I thought would be a printed-out roadmap to soil nirvana turned out to just be the beginning of building out my fertilizing future. The moral of the story? Yes, you should absolutely do a soil test, sooner rather than later. But your results may leave you with more questions than answered, so be ready to research the best way to feed your soil to feed the plants you grow!