The sweet potato, an economical crop choice, is also a good crop for farmers who want to grow organically or who face the threat of drought, as it requires few inputs.
Small-scale tobacco farmers in eastern Kentucky looking for alternatives to tobacco are discovering that an easy, potentially profitable transition lies in sweet potatoes. With relatively low input and capital costs and a short learning curve, growers can earn gross returns of up to $7,000 per acre, mostly through local sales.
"Sweet potatoes are a pretty good alternative, at least for our growers, because a lot of the equipment they used for tobacco can be used for sweet potatoes—particularly the transplanters—so they don’t have to buy a lot of new equipment,” says Tim Coolong, vegetable specialist at the University of Kentucky Extension. "Economically, it’s been very good for them.”
Coolong received a 2009 Sustainable Agriculture Research and Education grant to research and demonstrate sweet-potato growing on several farms and has helped about 15 farmers—most, but not all former tobacco producers—grow the highly nutritious root vegetable.
Meanwhile, in Mississippi—the country’s third-largest producer of sweet potatoes—SARE-funded research helps the state’s growers adopt sustainable practices and cash in on organic sales by showing them how they can better manage their soil with cover crops and conservation tillage.
Only one grower in Mississippi currently produces organic sweet potatoes, yet organic can fetch a premium at farmers’ markets and through sales to processors, particularly for baby food, says Mississippi State University researcher Ramon Arancibia. "Companies like Gerber don’t want pesticides, or even a lot of fertilizers.”
Working with three farmers around Vardaman, Miss., and others in Arkansas, Arancibia’s trials showed that an organically grown crop suffered far less pest damage than a conventionally grown one. In addition, he focused on showing the soil building qualities of cover crops.
"Sweet potatoes are root vegetables, so they need a very healthy soil. Also, the soil structure needs to be very good so the potatoes can grow in a nice shape,” Arancibia says, referring to cover crops’ ability to improve organic matter and loosen hard-packed soils.
Arancibia is sharing his findings with the 104-member Mississippi Sweet Potato Council, which represents nearly all the state’s growers. One farmer who collaborated with Arancibia is planning to plant a brassica cover crop on 50 acres next season, to see if it will combat nematodes.
Back in Kentucky, Coolong’s on-farm trials showed that aside from using pesticides to control wireworm damage, sweet potatoes require few inputs—and some growers are, in fact, pesticide-free. Sweet potatoes have low nitrogen needs and, in eastern Kentucky, do not require irrigation except in the case of extreme drought.
"There are a lot of nuances with sweet-potato production that this grant really allowed us to look at,” says Coolong, whose work translated into a detailed handbook and the formation of a regional growers’ association.
Two areas that require more work, he says, are establishing overwinter storage facilities and production of slips, the sprouts that come off a potato and turn into new plants. Slips are not grown locally and are expensive to buy from out-of-state producers, so showing local growers how to produce their own presents another opportunity.