Environmental Fridays

The dirt on dirt: Why we should care about unhealthy soil

On my first day of sophomore year, I committed the cardinal sin of any soil science class: I referred to soil as “dirt.” The gasp and dramatic correction that this elicited from my professor fueled the class to humorously continue calling his lectures “dirt class,” but truthfully it is an important distinction to make—one which draws attention to the need to improve our farming practices before it’s too late.

Soil, on one hand, is a layered, rich depository of life sustained by organic matter, from earthworms to microscopic fungi and bacteria. Dirt is simply soil that has been displaced and can no longer host the useful slew of organisms needed to grow healthy food. I’m no Nietzsche, but essentially: Dirt is dead.

Why should this matter to UK students? Because 95% of food is grown in soil, yet one third of the world’s soils are depleted. Thus, returning dead dirt to healthy soil is one of the most imperative issues of our time.

Historically, pulled weeds were often left on the top soil, which provided carbon as it decomposed. Thus, man only needed to till the soil once a year for planting, further integrating carbon into the mix of nitrogen phosphate, magnesium, and other naturally occurring compounds. As organic matter is introduced, the nematodes, fungi, bacteria, and myriad other beneficial soil organisms have a field day, so to speak; they blow off of around 60% of organic matter as carbon dioxide. Within 100-200 years, even with infrequent tilling, the soil is depleted of enough organic matter to sustain these organisms.

From ancient Greece to the American Dust Bowl, declining soil fertility and eroding topsoil because of tilling has led to the demise of civilizations.

In modern times, we’re pretty attached to our civilizations and thus employ inorganic fertilizers and pesticides to retain soil viability in over-farmed areas. These measures, however, have their own detrimental impacts, from phosphorous-induced hypoxia in waterways, to the myriad of claims against pesticide use.

According to the Food & Agricultural Organization, 58% more food could be grown if we used regenerative farming methods. There’s also the added benefit that healthy soils sequester carbon, lowing greenhouse gas concentrations.

UK students can help by bringing this knowledge to our own, or community, gardening endeavors. Planting a variety of different species of plants, with minimal digging, and keeping soil covered with either plants or mulches of organic matter can be key to revitalizing your soil. Our past article on composting provides info on how to compost and why introducing oxygen by turning is so important (most aerobic soil organisms can’t last more than 20 minutes without oxygen)! Another option is buying locally sourced, well-turned compost form the local Lex non-profit, Seedleaf.

In this article, an adorably-badass biologist-geologist-husband-wife-gardening-duo likened soil to the “gut of the planet,” and organic matter to its “lifeblood.” Let’s keep Mother Earth’s gut healthy, so that she can continue to care for ours, too.