Why I’m a soil farmer
The daily reminders of a rapidly warming planet have made me an avid student of anything that can help offset greenhouse gas emissions. So I grow food, but I think of myself as a soil farmer first.
When I got out of bed this morning I checked the weather report. It’s the first thing I do every day. When you grow food, the weather assumes a make-or-break urgency that defines your life. It also forever changes the way you relate to a forecast. I never hear “early frost” without worrying it could interrupt my ripening tomatoes, or “heat spike” without fretting over wilting spinach.
I started monitoring the weather in my early 20s, while running a market garden in the Pacific Northwest. It only took a couple of years of farming to notice the rains were becoming more torrential and the droughts, unusually long. After a cloud of new southern pests threatened to take down my crops one summer, I started thinking about the effects of global warming on a daily basis. It’s what drove me back to school to study soil and water management. I wanted to find a way to adapt to the changes I’d observed.
“After a cloud of new southern pests threatened to take down my crops, I started thinking about the effects of global warming on a daily basis.”
Daily reminders of a rapidly warming planet has made me an avid student of anything that can help offset greenhouse gas emissions. So I grow food, but I think of myself as a soil farmer first. I’ve learned that cultivating soil rich in microbes and organic matter can draw down excess carbon dioxide. Rebuilding the soil is the basis of regenerative farming, which rejects the use of synthetic pesticides and fertilizers and aggressive tilling. Instead, we lay down thick layers of mulch and compost. We plant deep-rooted perennials. And we grow cover crops that protect the soil from erosion.
I love the rich loamy soil I’m producing and I swear the food I’m growing is tastier. But what most intrigues me about regenerative farming is the powerful role it could play in cooling our environment.
how plants fight global warming
Plants are the ultimate and cheapest way to suck excess carbon dioxide out of the air. Almost all atmospheric carbon passes through plants during photosynthesis, the process that turns carbon, sunlight, and water into sugars and carbohydrates. Plant roots release carbon-rich sugars that feed organisms in the soil. In exchange, these critters make nutrients in the soil available to the plant. As plants die back each winter, they drop leaves and branches and even the roots die off. Over time this debris decomposes, adding even more nutrients and carbon to the soil.
The soil holds twice as much carbon as the atmosphere. Most of the carbon stored underground comes from plants through photosynthesis. As plants flourish, they produce carbon-rich sugars and carbohydrates that travel to the roots and trap carbon below our feet. Illustration by Krishna Chavda
The alliance between plants and soil organisms helps lock carbon in topsoil, producing the dark organic matter every gardener lusts for and turning the very ground we stand on into a giant carbon sponge. One tree, for example, can draw down more than a ton of carbon dioxide over its lifetime. Leaving the soil undisturbed and protecting the soil from erosion helps to keep the carbon in the ground and out of the atmosphere. This ability to capture greenhouse gases is why many experts believe regenerative agriculture, also known as carbon farming, could play an important role in fighting climate change.
Rise up citizen gardeners
Planting a garden is a powerful act. It gives each of us with access to a little dirt something we can do about the most significant threat we’ve ever faced. Cultivating even a little patch of soil, in pots or in your backyard, matters. Eric Toensmeier, author of the Carbon Farming Solution estimates that his own tiny carbon-rich backyard garden, about a tenth of an acre, can offset the carbon emissions of one American adult per year.
“Planting a garden is a powerful act. It gives each of us with access to a little dirt something we can do about climate change.”
Creating a giant, cooling carbon sponge significant enough to reverse global warming requires an army-sized regenerative effort, not to mention persuading farmers around the world to adopt these practices. Given the political challenges, that’ll be tough. But we’ve already got a decent head start.
While fewer and fewer people are farmers by profession, many Americans are growing food. In fact, 35 percent of us, or 42 million households, report growing some of our own food, according to the National Gardening Association of America. Large-scale adoption of regenerative farming practices would go a long way toward reversing global warming. The Rodale Institute estimates we could sequester more than 100 percent of annual carbon dioxide emissions worldwide if we switch to regenerative agriculture techniques to grow our food.
Experts agree more research is needed to understand the full potential of regenerative growing but there’s no question that even a small increase in soil carbon can improve crop resilience, reduce chemical use, conserve water, and offset greenhouse gas emissions. Just as exciting, it’s pretty easy to build rich soil. Your location, and the amount of space and time you have are important variables in successful gardening. But the regenerative basics stay the same.
Here’s what it takes to start your own soil-building garden.
Step one: Test your soil
The white strings of mycorrhizal fungi form a network of fibers that help plants absorb more nutrients. photo: MPGranch.com
Taking measure of your soil’s acidity and nutrient levels can get you off to the right start. A quick test can signal, for instance, whether you need to pile on more compost or other fertilizers, or loosen compacted soil. I’ve built testing into my annual routine and recommend that you do, too, because it’s an easy way to monitor the health of your soil. Most state universities can test your soil inexpensively and give you a detailed profile that includes pH and nutrient levels. That said, testing the quality of your soil isn’t absolutely necessary for regenerative gardeners given you’ll be treating it with a healthy dose of compost and mulch every year. And if getting a test stands in the way of you getting started on your own garden, don’t bother.
Step two: Build permanent beds
The hardest practice for me to adopt on my way to becoming a regenerative grower was low-till farming. Running a big metal rototiller through dirt is a really efficient way to break up weeds and grass and dig seed furrows. Unfortunately, this machine also breaks apart the soil’s natural structure and the living soil community that works so hard to nourish plants.
The broad fork is a handy tool for loosening raised beds without disturbing the soil.
Instead, I’ve learned to grow plants on permanent raised beds made from layers of cardboard or newspaper, leaves, grass clippings, compost, and any other organic material you can get your hands on. With permanent beds, you can leave soil organisms alone so they can go about their lives, breaking down organic matter, recycling nutrients, and aerating the soil. The structure they give the soil makes for good drainage, wicking away excess water in the winter and spring so roots don’t rot while keeping soil moist but not soggy in the summer.
I recognize that not everyone has the space or the interest in building a raised bed. No worries there’s another way to prepare your planting area: add more soil. Shovel on soil from anywhere in your yard, as long as you’ve first removed all the weeds. If your yard is too weedy or hard to dig up, or just not all that big, buy a few bags of soil from your local garden center. Make sure any soil you buy is clear of debris. I mention this because poor-quality leftover construction fill is sometimes rebranded as garden soil. Add enough soil so the bed is three to eight inches high. Any higher and you run the risk of having soil wash away during big storms or intense rainfall. Plus, it may dry out more quickly.
“An excellent way to get your hands dirty is to sign up for a community garden. Or offer to help in someone else’s garden.”
Maybe you don’t have a yard? An excellent way to get your hands dirty is to sign up for a community garden. Or offer to help in someone else’s garden. If neither is an option, you can grow in containers set out on a balcony or porch.
Container growing is easy as long as you pick the right size and start off with good soil. The bigger the pot the better because rootbound or crowded plants don’t weather outdoor temperature swings well and typically need more tending. A good rule of thumb is to choose a container that offers as much space below ground as a mature plant’s foliage above ground.
I like to fill my containers with homemade potting soil that's a mix of equal parts peat moss or coconut fiber, good garden soil, compost, and sand. But you can also buy potting soil from your local garden store. Look for potting soil that is 100 percent organic and, if you can find it, inoculated with mycorrhizae, a fungus that works with plant roots to absorb more nutrients.
Step three: Mix in perennial foods
Artichokes, asparagus, rhubarb, strawberries and garlic. These are all examples of perennial foods, which are hardier than annuals and marry well with regenerative goals. Any plant can be grown using a soil-first approach, and be tastier and more resilient for it. But perennials are a great choice because they require minimal to no soil disturbance and can stick around for many years.
Raspberries are among my favorite perennials because they make a beautiful natural border against pests and ripen early in the spring
One reason they do so well is because they’re anchored by extensive root systems that help them find water and nutrients deep in the soil. Deep roots also give these plants staying power when they’re buffeted by heavy winds, rains, and snow. Having the same plants in place for years makes it easier for all the soil-enriching organisms—the bacteria, fungi, and bugs—to gather and multiply.
More than 100 different varieties of edible perennial vegetables and fruits grow well in North America.
Step four: Compost and mulch
Regenerative gardening is unique in how much emphasis it puts on soil health. Improving your soil by adding compost and mulch, which you can make yourself or buy from a garden supply store, means your garden won’t need as much water, pest management, or other caretaking.
Keeping your garden mulched helps prevent soil erosion, suppresses weeds, and protects plant roots from becoming exposed and susceptible to drying out or freezing.
Compost and mulch work their magic better if used together. Basically, compost is what you mix into your soil, and mulch is what you lay on top of it. Compost is packed with nutrients like nitrogen, phosphorus, and potassium. It also has plenty of the trace minerals left out of synthetic fertilizers, like iron, zinc, and manganese. Refreshing the mulch around your plants helps prevent erosion of your compost and rich topsoil, keeps nutrients in the ground, and protects plant roots from becoming exposed and susceptible to drying out or freezing.
Just as it’s important to apply compost and mulch when getting your garden beds ready for planting, it’s important to replenish these layers with every planting season. Both compost and mulch help keep moisture in the ground by increasing the amount of carbon-rich organic matter. Enriched soil offers plenty of nutrients to support plant growth and holds more water than mere dirt thanks to an open structure with plenty of space between soil particles to let in air and water. These favorable conditions make plants sturdier and more resilient, a big plus in these climate-challenged times.
Once you plant your garden, consider adding it to the Climate Victory Garden Map by Green America. That way we can see the cumulative power of planting a garden to heal the planet. So let’s grow some good food. It’s time.
Acadia Tucker is an author, climate activist, and regenerative farmer and gardener who lives in Maine. Her book, Growing Perennial Foods: A field guide to raising resilient herbs, fruits, and vegetables is for sale on Stone Pier Press and Chelsea Green. Her second book, Growing Good Food: A citizen's guide to backyard carbon farming is available for preorder.
