At Coverdale Farm Preserve, the Delaware Nature Society Embraces Agricultural Practices from the Past

Along Wilmington’s Winding Way Road, verdant hills roll into picturesque pastures hugged by old oaks, maples and poplars that watch over Coverdale Farm Preserve. Evoking an Andrew Wyeth or Peter Sculthorpe painting, the historic stone farmhouse and barn were once owned by the family who donated these 377 acres to the Delaware Nature Society nearly two decades ago. Cattle graze on sweet grasses while a herd of goats gets into trouble nearby and a pair of muddy pigs snoozes snout to snout, seemingly smiling. A symphony of bird caws, chirps and clucks fills the air, along with the aroma of hay. 

A few yards from the farm’s vibrant vegetable garden and market, my 2-year-old plays peekaboo with a flock of fuzzy sheep through a rustic wooden fence. This is where the community gathers once a week in the summer and early fall to collect their CSA (community supported agriculture) harvests, socialize and get a healthy dose of vitamin N (for nature). 

Coverdale Farm is a happy place, and an event of this kind is at the heart of Delaware Nature Society’s mission to connect visitors with the earth and improve the environment through education and sustainable agriculture. “We’re developing the farm as a living classroom,” says Michele Wales, Coverdale’s manager, whose team offers ecological and culinary courses to deepen this connection between people and what’s on their plates. 

What lies beneath: A thriving ecosystem 

What’s at the root of sustainability? Wales points to the dirt beneath our feet. “Soil is a highly diverse, rich ecosystem,” she says. 

This moist, slightly sweet-smelling “dirt” we don’t think much about is home to billions of live organisms. It’s as essential to our existence as clean water and air. “These organisms range from single-celled bacteria, algae, fungi and protozoa to larger, more complex earthworms, insects, small vertebrates and plants,” Wales says. 

Each plays a role in the health of the soil, which provides nutrients and support for the very plants we grow and eat—directly from the ground or indirectly through the livestock that eat them first. 

“I liken healthy soil to a beautiful natural sponge,” says Wales. “It has pore spaces large and small that enable air and water to enter from the surface. They also allow the effortless movement of air, water, nutrients and biota below the surface.” 

A vegetative layer is also critical to helping this “sponge” thrive. Strong soil is resistant to erosion from forces like wind and water, and prevents runoff during heavy rains, keeping fertilizers and other harmful chemicals (if they’re used) out of the watershed. Perhaps the most important way healthy soil protects the environment is by naturally storing carbon, the chemical element that gives soil its rich black color. 

Carbon is found in all living organisms, including the bacteria and critters below ground, where it exists in solid form. While most of the Earth’s carbon is stored in our oceans, it’s also in soil. This is why soil plays a significant role in maintaining a balanced global carbon cycle. When it’s disturbed through traditional farming methods like tilling and plowing, the organic carbon mixes with oxygen and sun to create carbon dioxide, the toxic atmospheric gas that’s the main cause of manmade climate change. 

“Farming that breaks up the soil and leaves it barren for long periods robs the soil of organic matter, without paying it back,” says Jeffrey Dukes, a professor of biological sciences and a member of the Ecological Society of America. “Plants— and especially their roots—contribute carbon compounds to the soil that serve as food for microbes and other organisms. Without carbon input from plants, the soil food web can’t thrive.” So, farming systems that keep living plants in the soil for longer periods of time are more likely to maintain, or even build up, the soil’s organic matter, which in turn contributes to the fertility of the soil and to its ability to take up and retain moisture. Coverdale decided about six years ago to stop using chemical fertilizers. “In both animals and production, our primary focus is the soil,” Wales says. “When you focus on that, everything else is easier.” 

To foster a diverse ecosystem and rebuild the health of the soil, Coverdale’s forward-thinking farmers are turning to “regenerative agriculture”—a millennia-old method that mimics natural processes by using livestock to farm their own land with rotational grazing. They’ve devised a three-phase plan that began in 2016 and aims to better the environment while also being economically viable. “We’re moving toward a system that honors the land,” says Wales. “As an environmental organization, we have a responsibility to demonstrate sound land stewardship in a way that’s restorative and not damaging or destructive. As a nonprofit, we receive support to help us do that in ways that other farmers can’t. Because of that, I feel we also have a responsibility to pay it forward and to teach people how to do it.” 

Coverdale can also build a business that is sustainable by feeding the community in ways that are outside the garden box. They do this by working with restaurants and markets throughout the region. 

Rotational grazing boosts soil regeneration

It’s now early winter, and Wales gazes out into the swath of muted green pastureland punctuated by a single spiny oak tree. Looking out over the 80 or so acres of grazing fields, it’s easy to see how over-farmed, impervious soil could send erosion from the rolling topography into the adjacent stream, impairing water quality. “Envision this in a beautiful, green, lush vegetative state,” says Wales, explaining what will happen in the coming months. 

Soon micro-pastures—about an acre or two in size and separated by poly-wire fencing—will be built across 50 some acres. The rotational grazing process will rely on cows, sheep and poultry, in that order, to “mow” warm-season grasses, legumes and herbs that will be planted. Clovers and field peas bring nitrogen from the air into the soil, while strong-rooted plants stabilize it. “This robust vegetative planting mat is palatable to all native species and will provide service to the soil,” Wales says.

In a follow-the-leader system, about 50 cows will “mob graze” the first micro-pasture. “It might take an hour or a whole day, but they’ll ‘mow’ their portion of the vegetative layer,” says Wales. 

The cows disperse their nutrients (urine, manure) evenly around the field before moving on to the next pasture. Next, a dozen sheep “grass manage” what the cows have left behind in the first pasture, followed by 100 chickens and turkeys, who aerate the soil and control pests. Differing manures provide a diverse nutrient profile. Cycles last 40-60 days, allowing the land to breathe in between. 

“The birds serve a great function,” Wales says. “Flies lay eggs in cow manure, which generates more flies, which are very stressful to cattle. The chickens will scratch apart this manure and spread it out—reducing larvae and flies.” 

Cows also control pests for the more fragile sheep. “Sheep are affected by parasites that live at the soil line, which can make them anemic. Like vacuums, the cows inhale some of these parasites. So you have a sort of bookend pest control, with cows at the front and birds at the end. In the middle, the sheep are spared exposure to pests that their systems won’t tolerate, as well as those of the other animals.”

Wales and her team began working with the animals in isolation last year to learn how long it takes each animal to graze a certain area. She estimates that, once they graduate from the experimental phase to production, it’ll take about five years to achieve their desired soil quality.

The pigs and goats aren’t part of the regenerative agriculture system, but they do provide their own essential functions on the farm. “Pigs are our cleanup crew,” Wales says, motioning to a decaying pumpkin patch. They also eat pests and turn the soil slightly. Goats are “browsers” that help manage invasive plant species, like milkweed, which is poisonous to cows. This is a relief to her team, because the milkweed is what supports the beautiful monarch butterflies. “We want to have the cows and butterflies coexist,” says Wales. 

Planting hedgerows of fruit and nut trees is also part of the new system, attracting even more biodiversity. An ornithologist visits the site to count the birds alone. “We hope to create a robust ecosystem,” Wales says. “We’re tracking not only the health of the soil, but also the insects, mammals, reptiles, amphibians and other wildlife we’re finding on the farm. This grassland isn’t just for the cattle. It’s also for birds to use for part of their life cycle—whether it’s to feed, lay eggs or fledge their young.” 

In a field adjacent to another small barn where the market is held, seven acres of garden await a new organic high-quality soil that will foster the growth of cabbages, swiss chard, kale, squash, edible flowers and other tasty vegetables. “Different crops demand different things from the soil, so crop rotation gives soil a chance to heal,” says Wales. 

Between rows of this colorful patchwork quilt, strategic “buffer zones” of native plants attract insects—pollinators and predators—that benefit whatever crops are growing there at the time. Elsewhere, climate-controlled hoop houses nurture a cucumber jungle, where vines of the crispy green fruits dangle from trellises. There are also eggplant varieties and the juicy tomatoes that are in such high demand. These houses allow Coverdale’s farmers to extend the growing season of the crops to meet the needs of the community. 

Wales and her team also employ precise drip irrigation, avoiding any water going to waste. On the periphery of the farm, tall grasses have been planted to capture any that does escape, further protecting water quality in running streams. Instead of tractors, tarps are used to terminate vegetation, robbing plants of access to light and moisture. “The garden is managed by human hands more than anything else,” Wales says, “with small machines occasionally doing some intentional soil work.” 

The barn contains a propagation house for seedlings, as well as a full-service kitchen where Wales teaches culinary courses like “Three Ways to Prepare Tomatoes that You’ve Never Thought of.” Her mission is to make people think about food differently, diversify their palates, and prevent waste by sharing exciting options for foods they might be getting tired of toward the end of a growing season. 

In addition to educating the community through classes and school field trips, special events and weekly CSA markets, Wales hopes to take Coverdale’s product into the community, where it can feed more people. “We want to feed a more diverse community—not just the people who can afford a CSA,” she says. 

Wales and her team also hope that other farmers can benefit from what they continue to learn at Coverdale. “Even if you can’t mimic everything we do, if there are things we can share to help you make your farm more environmentally sound, that’s our job,” she says. “Right now, we’re suggesting it’s possible—but we have to do it.”