Back to the basics: Simple Gifts Farm tests pedal-powered tractor to deal with weeds

Daily Hampshire Gazette, May 26, 2017, by Scott Merzbach

AMHERST — Weeds are a major cause of crop failure at organic farms, making the equipment used in controlling their growth important to the successful production of fruits and vegetables.

“After harvesting, it’s our biggest labor,” says Jeremy Barker-Plotkin, who runs the 50-acre Simple Gifts Farm in North Amherst. “Everything we do is with weed control in mind.”

To effectively eliminate weeds, gas-powered tractors are deployed at least once a week, traveling through the rows of crops with various kinds of weeder attachments designed to stir up the soil next to the plants.

Recognizing that there might be ways to cut back on the farm’s dependence on fossil fuels — and at the same time get himself more exercise — Barker-Plotkin this week began using a new pedal-powered tractor, called a Culticycle, for weeding that could supplement, and possibly even replace, more conventional equipment such as tractors.

“If we can run the weeders with one-person horsepower, it would reduce fossil fuel use and be more sensitive in the way we do things,” Barker-Plotkin said.

The Culticycle is the creation of Tim Cook, a member of what is called the Farm Hack community, a group of inventors who are part of a make-your-own-machines movement that aim to solve problems for farmers and share their innovations online.

Barker-Plotkin first saw the Culticycle at an annual meeting of the New England Berry Growers Association more than a year ago and, after getting a $2,500 grant from the Grinspoon Foundation last spring, bought the equipment from Cook, who runs Green Tractor Farm in the Boston area.

But Barker-Plotkin was not immediately able to get it into the fields. Cook first assembled the Culticycle from parts from a lawn tractor, an all-terrain vehicle and a bicycle, and then had to design it to fit Simple Gifts’ fields, where crops are planted in rows 6 feet apart.

Following this, Cook had to figure out how the basket weeder, which weighs about 100 pounds, could be easily raised and lowered using a counterbalance to push through the soil next to smaller-seed plants, such as spinach, arrugula, carrots and beets, that are planted directly into the soil. The basket weeder makes a layer of dust mulch and causes more air flow to the soil, bringing the plants enhanced nutrients.

In the latest Culticycle, the basket weeder is lighter and thinner, meaning it can only remove weeds from one side of the plants at a time.

Other refinements have included a lower gear ratio for easier pedaling and tighter steering so the bike cultivator’s rider can nimbly turn the machine around in the field.

The 3 to 4 mph speed depends on the choice of gearing and the pedaling ability of the operator.

“It worked well, but it was a fair amount of effort,” Barker-Plotkin said. “It’s definitely slower than doing it with a tractor. But it’s doing the job we needed it to do.”

Barker-Plotkin was able to work on about one-third of an acre in 90 minutes. With 2 acres of crops where the basket weeder is used, the task could take about six days to complete. Extended dry periods may be the best opportunity to deploy the Culticycle, he said.

Currently, the Culticycle is being used in place of a lightweight, 30 to 35 horsepower tractor that still burns a lot of gas. It takes about 5 gallons to do 1 acre, Barker-Plotkin said, so over the 20 weeks or so of the growing season, the equipment could reduce use of gas by 100 gallons.

He understands that the Culticycle is a work in progress and appreciates the efforts Cook is still undertaking to make it better.

“The bike cultivator is a bit of a risk, it’s an untested concept,” Barker-Plotkin said.

Cook said in an email that he made the early versions of the bike cultivator between 2006 and 2008, and by 2009 was using a version to cultivate tomatoes.

“Around that time a lot of people were into the idea of becoming more collaborative about the problems faced by small farmers: environmentally, we should all be working toward a much larger number of much smaller farms and these farms should try to figure out how to reverse the reliance on petroleum and chemicals that has been increasing over the past century,” Cook said.

Barker-Plotkin said he believes there will be several benefits that include the reduced fuel use and lower costs, less soil compaction and enhanced weed control by getting closer to the plants.

It’s not yet certain if a second piece of mechanized weed control pulled by tractors through the fields once a week, the Finger weeder, can also be attached to the Culticycle. That weeder goes into the seedline and, with the “fingers,” pokes between the plants and stirs up the soil to kill the weeds. That is primarily used for any transplanted crops and vegetables with large seeds, such as corn, beans and squash.

Noting that he has recently taken up jogging, Barker-Plotkin said he may be able to replace that exercise with one he does for his livelihood.

“One of the ideas of this for me personally, as a farmer I’m active, but I don’t get a lot of aerobic exercise,” Barker-Plotkin said. “I’m psyched about this from the perspective of someone without a lot of aerobic exercise.”