Growers and researchers have shown that reduced-tillage production systems are effective in maintaining yields and profitability while promoting sustainability.
No-till systems, where growers plant cover crops rather than till the soil, and strip-till systems, where they till only a narrow strip where the vegetables or fruit trees are planted, have become fairly common for items such as pumpkins and winter squash.
But they’re often overlooked when growing other items, such as tomatoes.
Research dating back a decade or so from the Beltsville Agricultural Research Center in Beltsville, Md., shows the benefits of using conservation tillage with tomatoes, says Gordon Johnson, vegetable and fruit specialist for the University of Delaware Cooperative Extension in Dover.
“We included that production system in our recommendation books,” he says.
Implementing a no-till or strip-till program where it makes sense can be a “nice addition to a diversified, sustainable farm with a heavy cover crop base,” Johnson says.
Others also have proven the worth of reduced-till systems with tomatoes.
Guy Moore, whose family owns Larriland Farm in Woodbine, Md., and who serves as president of the Maryland Vegetable Growers Association, grows primarily on silt loam soil, which he says is very productive but must be treated carefully.
A grower can ruin the land if he tries to work it while it’s wet, Moore says. But a no-till system and cover crop make working a wet field easier.
Larriland Farm is a 280-acre U-pick operation that features 4 acres of roma, cherry, round and yellow tomatoes.
Weekends are the farm’s busiest days, but even a rainstorm on Thursday night won’t prevent visitors from going into the field on the weekend, thanks to the no-till system.
Moore does his first planting on black plastic and his second planting, when temperatures begin to warm, with a no-till system.
Conservation tillage yields are similar to those achieved on black plastic, he says. Moore uses a homemade no-till transplanter based on a design of a modified conventional transplanter developed at Virginia Tech.
Dave Meyers, senior agent for the University of Maryland’s Anne Arundel County Extension, says he’s a “real strong proponent of strip-till production” because limited tillage in the plant zone provides many of the benefits of no-till and conventional till systems.
“We’re seeing some significant gains in that,” Myers says.
Reduced tillage and cover crops also can help produce healthier crops.
Tomatoes are susceptible to early blight, but a ground cover can delay the onset of the disease and minimize its severity, Moore says. It also helps reduce erosion.
The process helps prevent soilborne diseases, such as buckeye rot, Meyers adds, and can reduce injury from heat stress and prevent sunburn.
A drawback of reduced-tillage is that your tomatoes will mature later because they lack the warmth provided by the black plastic, Moore says. Weed control also is more difficult with no-till.
Strip-till programs provide warmer soil than no-till, but not to the extent that plastic mulch provides, Johnson says.
On the plus side, a reduced-tillage system helps extend the season for anyone who grows for local farmers markets, Meyers says.
The lack of availability of no-till transplanters is another drawback that sometimes discourages growers from adopting reduced-till systems, says Steve Groff, owner of Cedar Meadow Farm in Holtwood, Pa. Like Moore, Groff built his own transplanter.
Cover crops matter
Don’t overlook the role of the cover crop.
“Cover crops are as much of an integrated part of your production system as the crops that you’re growing,” Johnson says.
Research released by Autar Mattoo at Beltsville in 2009 shows that “planting tomatoes in fields of killed and rolled hairy vetch, which serves as a mulch, activates some of the metabolic pathways and genes that make tomato plants more vigorous—and their fruit more tasty and nutritious,” according to the center’s website.
Groff, who now grows tomatoes in high tunnels and greenhouses to ensure consistent quality, previously used a reduced-tillage system with a cover crop comprising hairy vetch, cereal rye and a couple pounds of Tillage Radish, which he planted in early fall. The radishes decompose, creating winter kill, and rye and vetch grow in spring.
The day of the transplanting or even a couple of weeks before, he would knock down the vetch and rye with a roller. Then, with the no-till vegetable transplanter he designed, Groff would plant the tomatoes into the rolled-down cover crop.
Moore uses a cover crop of sudex—a sorghum-sudangrass hybrid—in the summer and winter rye in late fall. And Meyers says he always uses a cereal rye cover crop because it is easier to time the burndown and easier to use strip-tillage machines in.
A no-till system is probably “somewhat less expensive” than conventional tillage because the process requires fewer trips across the field, Moore says.
Costs typically are less than conventional plasticulture tillage because you’re not committed to full tillage, which requires several more operations, such as preparing beds and layering plastic, Meyers says.
There’s also the expense of the plastic and drip tape.
However, Meyers suggests using drip tape irrigation, even with strip- or no-till production.
“Beyond that, it’s just the cost of the cover crop and the no-till or strip till machine,” he says.
It’s been proven that reduced-till systems work, Johnson says. “The next step is to increase adoption where it makes sense.”
Growers must ask whether the system is appropriate for their farms, and many times the answer is yes, he says—especially in hilly areas and regions where erosion is a problem.
“You have to have equivalent yields to justify adopting them,” Johnson says. Until some major growers adopt the conservation-tillage practices with tomatoes and spread the word about how effective they are, growers likely will stick with the tried and true plastic mulch system, he says.
Cultivation can replace herbicide strips in orchards
Strip spraying apple orchards may do a good job controlling weeds, but it also can increase chemical costs, soil erosion and nutrient loss, and reduce beneficial insect habitat, says Matthew Grieshop, assistant professor at Michigan State University’s entomology department in East Lansing.
But Grieshop and his research team have learned strip cultivation can help you achieve about the same level of weed control at a lower cost while benefiting the soil.
Grieshop’s studies, based on work conducted at Cornell University, show that strip tillage in apple orchards can reduce ground cover—or weeds—compared with no treatment and provide results that are at least equal to herbicide strips.
The studies also indicate that strip cultivation does not reduce organic matter in the soil, which could lead to nutrient leaching.
In many cases, cultivation resulted in increased levels of ammonium nitrate during July, when trees typically size their fruit, Grieshop says.
Predatory mites also were more abundant in cultivated rows compared with non-cultivated rows.
The studies were conducted in 2010 and 2011 and will be expanded this year and next, thanks to a federal grant, Grieshop says.
He estimates that growers can save about $75 per acre using strip cultivation.
Grieshop’s team had the best results with the Wonder Weeder tillage implement made by Harris Manufacturing of Burbank, Wash.
It tills the top couple of inches of ground cover back into the soil. He does not recommend using a rototiller.
Jim Koan, owner of AlMar Orchards in Flushing, Mich., has used strip cultivation in about two-thirds of his organic apple orchards for 10 years and says he sees improvement in the soil profile every year.
He has not calculated precise monetary savings. But he says, anecdotally, the process saves him “a lot of money” compared with the herbicide strips he used when he grew conventional apples.
Short term, strip cultivation eliminates weed competition and knocks out pests, he says. Long term, it improves soil fertility and water-holding capacity.
Strip cultivation works best with high-density plantings, Koan says.
The practice also can help growers concerned about how using the popular herbicide glyphosate repeatedly may adversely affect their land and weed populations, Grieshop adds.