“Worm castings are the ultimate fertilizer,” Kevin Somerville says. With a flat-end shovel, he carefully turns the compost pile in a shallow, wooden bin to reveal a squirming ball of red earthworms. Kevin’s wife, Mary, shows us the tiny, white babies, not much wider than a piece of thread. The biggest of the worms is only a couple of inches long.
Joe digs his hands into the rich soil. “It’s warmer than room temperature,” he reports, “and slightly moist.” I’m too busy taking notes to stick my fingers in, but the soil looks soft, inviting, and well aerated.
Vermiculture, or worm farming, is an important element in the Somervilles’ plan for their 140 acres in Johnson County, Iowa. Just this year, they received certification as an organic farm. The compost they’re making will enrich the soil for next spring’s crops of organic hops, sweet potatoes, and alfalfa, as well as their family garden.
Taking a Scientific Approach
“If you have healthy soil,” Mary adds, “you’ll have healthy plants; they won’t be as susceptible to disease or bugs.”
The Somervilles take a scientific approach to creating healthy soil. “We had comprehensive soil testing done to measure the minerals in the soil,” Mary says. By learning which nutrients were needed, they could determine exactly what they should put into their compost pile to provide a healthy living environment for the worms as well as the best nutrient mix for their fields.
“It’s similar to human health,” Kevin says. “The land needs certain nutrients.” Some of those nutrients, the Somervilles purchase from Humus Health Organics in Kalona. “The rest,” he says, “we add as vegetative matter.”
About 12 months ago, the Somervilles constructed a large, flat bin in one of their outbuildings, then layered it with torn cardboard, shredded newspaper, grasses, and piles of pre-composted fall leaves. “We used a recipe,” Mary says, “to get the nutrients we needed.” When the bin was ready, they purchased 30 pounds of red wiggler earthworms from an organic worm farmer.
In optimal conditions, red wigglers will double their population in four months. In the past year, the Somervilles calculate, their 30 pounds of worms have become 240 pounds. “We call it ‘ranching underground livestock,’ ” Kevin says with a laugh.
They’ve built several additional bins to accommodate the expanding worm population. Three are currently in use, containing about a foot-deep mixture of red wigglers, black worm castings, yellow pieces of chopped organic hay, decomposed brown leaves, brown cinnamon sticks, and a variety of other herbs and spices. Sounds like an odd mixture, until the couple explains.
Earthworm Haute Cuisine
It takes a huge amount of plant matter to sustain a compost operation this big. The Somervilles have been highly resourceful in finding just the right materials to give the worms an ideal home. After all, the earthworms are the “machines” that process plant matter into rich castings (worm manure) for farming. It’s critical to keep these critters well fed and happily reproducing.
Stacked in the Somervilles’ barn are several pallets of 50-pound bags. At first glance, they look like sacks of animal feed or seed for the next year’s crops, but Kevin tells us it’s 100 tons of worm food. “We got a mother lode from Frontier Herbs in Norway, Iowa. I picked up two truckloads of herbs and spices from them just today. And there’s more waiting for me.” One hundred tons of herbs and spices? That seems like an expensive diet for earthworms.
“I got them through an exclusive agreement with Frontier Herbs,” he says. “It all started with a timely phone call. We needed more plant material, and Frontier Herbs needed a place to get rid of all the stuff they couldn’t sell. The spices might be outdated, or the bag might be torn open, or there might be material in the bag that makes it unusable. Our agreement with them is that this will only be used in our compost, not for anyone to eat.” It’s as good a deal for Frontier as it is for the Somervilles, as it keeps them from paying to dump the unusable food in the landfill.
We drive to another part of the farm and see two huge piles of decaying leaves. We see yet another example of resourcefulness. When nearby cities collected fall leaves, they needed a place to dump them. Again, the Somervilles were willing recipients of someone else’s vegetative waste. Here on their farm, Nature is recycling herself. Deep inside the piles, leaves are beginning to decompose. They’ll be used as pre-compost in the new bins the couple will start when the earthworms have finished the job in the current bins.
When the Somervilles determine that a bin of soil has been fully composted, they’ll sift out the worms using a “worm tumbler.” As the tumbler is turned, nutritious castings will fall out, and the worms will be gently captured in another container. The screen size optimizes collecting the smaller worms and eggs so little “livestock” are not lost. The collected worms are then redistributed into newly prepared bins, to start the composting process all over again.
The Somervilles will mound some of the new soil from their bins around the base of the organic hops plants their 24-year old son, Seth, farms on a portion of their acres. They’ll spread the rest on land for their root crops. Their goal is to sell all of their crops locally, to keep the carbon footprint of their farming operation low in yet another way.
Asked whether “anyone” can try vermiculture, even in a small yard, or if it’s just for farmers, Mary says, “There are composting kits of various sizes available on the market. We have a friend in Tempe, AZ who is feeding his worms on table scraps and vegetation from his yard. The worms are quiet little workers who need no care when you leave town for the weekend. It’s a great way to capture the household waste stream and reduce your trips to the lawn and garden centers for nutrients for your landscape or houseplants.”
“Big Ag has a ‘conservation ethic’ of planting fence row to fence row,” Mary says. “I wish they’d work toward a balanced landscape. If farmers would devote even five percent of their acres to conservation practices, such as adding buffer strips to keep water from running off, that would make a big difference in the stability of the soil.
“I compare it to tithing at a church,” she adds. “You set aside a small percentage for the greater good. But too many land owners choose not to farm in a conservation-minded way.”
Iowa farmers typically have limited biodiversity in their plantings, alternating crops from feed corn to soybeans in a regular rotation. Every few years, some farmers do another crop rotation and grow an alfalfa/grass mix to restore the nutrients. This family farm operates on a completely different philosophy. The Somervilles are conservationists who live their beliefs. The evidence is everywhere we look.
Essential Grant Support
When we first arrived, the Somervilles’ daughter, Kristi, showed us a restored a wetland area that had been drained off for farming. “Some farmers plant their wetlands, which end up being flooded year after year, anyway. They don’t get any crops to speak of, but they keep trying,” Mary says.
The Somervilles decided that allowing the land to return to its natural purpose and stay that way made better ecological sense. Restoring the wetland was partially made possible through a whole-farm conservation plan that included waterways and contour buffer strips. The land is a home for wildlife now, where once it had scant crops that used more in energy than it produced in food. From their house, they can see pelicans, wild turkeys, ducks and other water birds.
In two sections of their fields, the family has reestablished native prairies and used native species in their buffer plantings. They received some financial assistance through the Johnson County Soil and Water Conservation District. “With good burns, we’ll have a beautiful prairie,” Mary says. “We want to make pathways so people can enjoy it.”
With a Trees Forever grant, they brought in skid loader with a tree shearer attachment to battle back invasive species. Their goal was to start an oak savanna and allow the native prairie to flourish. “It takes a lot of time and effort to battle back invasive species. Once you get the native plants established, you just need to be patient, and eventually they’ll take over again. Our children and grandchildren will really enjoy what we are doing in our lifetime,” Mary explains.
Growing a “living snow fence” is another part of the couple’s plan. They planted three rows of various types of trees and shrubs to keep snow from drifting over the county road they use to access their farm. The row closest to the field alternates red osier and nine bark. The middle row is white pines. And the row closest to the road is two varieties of spruce. The project has yet to be evaluated for effectiveness, as it will take years for the trees to reach sufficient size to provide the needed barrier. “The tall prairie grasses between the trees and the road might be just as effective at capturing the blowing snow,” Mary says.
The grants and financial incentives the Somervilles have received come with strings attached. They require a tremendous amount of dedication, time, and hard work. But, along with the couple’s own resourcefulness, the funds provided are making their dream of sustainable agriculture a reality, leaving the world a healthier place for all of us.
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