By Jonny Lupsha, Wondrium Staff Writer
A strange new way to determine soil health involves burying underwear in it. Scientists in Switzerland will send 2,000 pairs of cotton briefs to volunteers who will bury them for future analysis. Other methods of testing soil health won’t scare your neighbors.
Swiss scientists are telling microorganisms found in soil to “eat their shorts”—literally. They’re sending 2,000 pairs of biodegradable cotton underwear to volunteers to be buried in backyards and, later, retrieved and returned to the scientists for analysis. Giving a new meaning to the term “soiled underwear,” this practice can measure soil health by detecting how thoroughly microorganisms in various soils consume the fabrics in the briefs.
Amateur greenthumbs can conduct at-home soil tests, too. Anyone curious about which kind of soil is in their home garden can figure it out with some tried-and-true experiments. In her video series The Science of Gardening, Dr. Linda Chalker-Scott, Associate Professor of Horticulture at Washington State University, said they’re inexpensive and effective.
The Ribbon Test
According to Dr. Chalker-Scott, since our fingers are so sensitive to texture, we can tell a lot about soil just by feeling it. However, the first step is to take a handful of soil and add just enough water to thoroughly moisten it.
“You want just enough water that you can form a ball, and later on, a ribbon,” she said. “What you want to do is get it in your hand and squeeze it, and it’s going to make a ball, and that ball is going to tell you a little bit about what kind of soil you have.”
Both highly organic soils and very sandy soils won’t form a ball at all—either one will fall apart. However, soil with a good amount of clay in it will not only hold together but will feel rather sticky. The next step is to make a ribbon out of it.
“You’re going to work it with your fingers and you’re going to see if you can flatten it into a ribbon,” Dr. Chalker-Scott said. “If [it’s] a true clay, it would be like modeling clay or a pottery clay, where you would be able to see your fingerprints as you pressed on it. But [if] I’m not seeing prints, I’m going to say that this is probably a clay loam.”
Other kinds of soil have particular characteristics. For example, soil that behaves like clay loam but feels grittier will likely have gravel in it, or more sand.
The Soil pH Test
The soil pH test may be less fun—there’s practically no playing in the dirt involved—but for newcomers to gardening or those with less confidence in identifying the soil by pressing it with their fingers, it’s reliable and informative.
“So there’s these kits that are very easy to find; very easy to use; and just requires water, your soil, and a reagent—and then, of course, a color chart to look at,” Dr. Chalker-Scott said.
According to Dr. Chalker-Scott, all that’s required is to put a bit of soil into a tube, add a reagent, add water, cap it, shake it up really well, and let it settle. As it settles, the grit in the soil will move to the bottom and the color will appear up top. While it settles, it’s a good time to think about how local climate determines pH balance.
“Climate is the overriding weather conditions—its temperature and its water—so even if you have a completely unnatural urban/suburban soil, its pH may be very similar to the pH of the soils in the same general area,” she said. “In my part of the country, on the West Coast, we have coniferous forests and it tends to be a very acidic soil.
“So the soils are made over eons, based on climate conditions, as well as the plants that have grown there for a long time, and that’s what’s going to determine your soil pH.”
Due to these conditions, it’s difficult to change the overall pH level in soil.
Whether testing by ribbon, pH kit, or “unmentionables,” soil is a nutrient-rich, complex mixture of earthen materials. Treated properly and paired with the right plant life, it can make a beautiful garden of edible and non-edible wonders.