Why Organic Matters: SOIL
This is Part 1 in a series about Why Organic Matters. We believe in organic agriculture for some very good reasons, and we'd like to share them with you. Join us in choosing a healthier future!
When was the last time you thought about dirt? Unless you're a gardener or a farmer, chances are it's not something you think about very often. Yet it's an enormous part of our lives. It's underneath our homes, our offices, our cars, and our feet. We walk on it everywhere we go, regardless of what's been built upon it. And, most importantly, our food grows in it. The UN estimates that 95% of the food we eat is grown in soil, either directly or indirectly. Soil provides the foundation for all life on Earth.
So what is soil, exactly? Soil is made of several layers, beginning with a nutrient-rich layer at the top called topsoil. This layer is where most of the earth's biological soil activity occurs, and it's full of minerals, air, water, microbes, animals, and various types of organic matter. Plants get most of their nutrients from topsoil, which is just a few inches deep. (Beneath the topsoil are layers of subsoil and bedrock). The organisms at the very base of the food chain rely on the soil, and all other living organisms (including us) rely on those basic organisms for sustenance in one way or another. Healthy soil grows healthy plants, and healthy plants feed healthy animals.
But what happens if the soil underneath our feet isn't healthy? And what's in it that's so important?
Soil contains organic matter called humus. The richest soils are high in humic acid, which delivers nutrients to plants, increases water storage in the soil, and regulates the soil's pH, among many other benefits. The soil also contains a host of microbes that nourish and protect the plants that grow within it. Just as human health is linked to the health of the microbiome in our gut, soil health is linked to the wellness of its own microbiome. The bacteria and fungi in the soil deposit nutrients into the soil, "digesting" them into a form that can be absorbed by plants. They also act as an incredible underground "brain" that allow plants to communicate with one another. If a plant is attacked by a pest or a disease, it sends out a "warning" to surrounding plants whose roots are connected to the same network of microorganisms, and healthy plants nearby will increase their natural defenses preemptively in case they're also attacked. Isn't that amazing? The ecosystem beneath our feet is rich and diverse, with an intelligence of its very own.
Tragically, modern commercial agricultural practices have rendered many of these microbes useless. By spraying chemical fertilizers, pesticides, and fungicides on conventional crops, many soil ecosystems have been destroyed. Conventional agriculture has also stripped several nutrients from the world's topsoils, resulting in produce that's less nutritious than the food our parents and grandparents ate. We've been depleting the soil for hundreds of years by harvesting more nutrients than we return, with the most dramatic losses occurring in the last two centuries. And disruptive farming practices have caused severe erosion, which itself causes further problems such as yield reduction and even greater nutrient depletion. These issues are systemic.
With half of the world's topsoil having been lost in the last 150 years, we're in a delicate position, to say the least. And when you consider that it takes 1,000 years to grow three centimeters of topsoil, the situation is dire indeed. About a third of the world's soil has already been degraded, and we're continuing to lose 30 soccer fields' worth of soil every minute. At that rate, we'll completely deplete the planet of its soil in just sixty years.
So what are we to do? We can't just run out and buy healthy soil at a store; it has to be grown. Well, it just so happens that organic agriculture is good at growing topsoil. In a forty-year assessment, organic farming was shown to improve the long-term quality of soil, improving its structure and increasing its ability to capture water (and thus reducing floods and drought). Organic soil has also been shown to contain 44% more humic acids than conventional soils. And a comparative study in India showed that organically farmed soils had significantly higher levels of zinc (44%), iron (21%), copper (7.5%), and magnesium (6%) than conventionally farmed soils.
Another way organic farming benefits the soil is by sequestering carbon from the atmosphere, which helps slow global warming. Since the beginning of mechanized agriculture, scientists estimate that we've released about 78 billion metric tons of soil carbon into the atmosphere in the form of CO2. This has contributed to climate change, accounting for 24% of global greenhouse gas emissions. But improved land-use practices could increase the amount of carbon stored in the topsoil by 0.9–1.85 billion metric tons each year. Soil holds about four times more carbon than the atmosphere, and it stores 80% of the earth's terrestrial carbon. Farming methods such as the use of cover crops and covering bare paddocks with hay or dead vegetation helps to sequester carbon in the soil. Grazing livestock in one concentrated area at a time (and rotating grazing areas often) also improves soil carbon levels by encouraging deeper root growth, drawing the element deeper into the soil.
Remember the microbiome of bacteria and fungi mentioned earlier? They play an enormous role in sequestering carbon. This is another reason organic farming is an important solution to improving the world's topsoils. Since chemical fertilizers and pesticides are banned according to organic practices, the soil's microorganisms are free to do their important work. They require carbon for food, contributing to the carbon sequestration process in combination with plants. The application of commercial agricultural chemicals disrupts this process, and in turn disrupts the natural global carbon cycle. But organic farming contributes to soil microbial health, enhancing its activity and increasing the abundance of microorganisms. This is another way in which organic agriculture is a good solution for protecting and growing the world's soils.
The Earth's soil is just one reason we believe in organic (and it's a good one!). We hope you'll stay tuned for more information about organic farming and why it's so important. For now, we hope you'll show our soil some love by buying organic!