Posted June 2, 2005: "Maybe
we got lucky, but it worked beautifully. Weed control was excellent."
Michigan State University extension specialist Dr. Dale Mutch
sums up his first year trying out an organic no-till system
using a cover crop roller based on the one designed and built
at The Rodale Institute®. Drilling feed-grade soybeans
into knocked-down cover crops of cereal rye and hairy vetch,
Mutch and his team obtained yields of around 60 bushels per
acre—in a year in which average soybean yields in their
area were just 40 bushels per acre.
Needless to say, results like that have been attracting attention.
Since the 2004 soybean harvest, Mutch says, he's presented
the results of the trial to a total of about 125 organic farmers
and 75 conventional farmers—and has gotten enthusiastic
responses from both groups. "I've got a lot more guys
interested in organic now than ever before," he notes,
"especially with organic bean prices as strong as they
While Mutch remains cautious about recommending the new system
to farmers, he's eager to subject it to a second year of testing
in his research fields at the Kellogg Biological Station (KBS)
in Hickory Corners, Mich. "We're on a sandy loam soil,"
he points out—farmers on different soil types may experience
dramatically different results. And again, they may have gotten
lucky with the weather: "Last season it rained every
day in May," he says—conditions that favored no-till
over standard tillage and that helped produce thick, vigorous
cover crop stands. This season, too, the system will spread
to Illinois, where one of Mutch's former post-docs will be
working with another, identical roller at a USDA-Agricultural
Research Service station in Urbana.
"We'd been playing around with [organic no-till systems]
for a number of years," explains Mutch, who specializes
in cover crops and IPM for low-input and organic farming systems
and manages eight OCIA-certified organic research acres at
KBS. Originally, they tried drilling soybeans together with
winter annual rye. With the rye planted off-season from its
normal habit, it was retarded in its growth and served to
hold back weeds without providing too much competition for
the soybeans. "That worked really well the first year,"
he notes, "but the second year was a drought year, and
it didn’t work." (They published a paper on the
results in the January 2004 issue of Agronomy Journal:
of Interseeded Winter Cereal Rye in Organic Soybean Production
Next, the team tried chopping a rye cover crop with a flail
mower and planting into the residue. Around the same time
they learned about The Rodale Institute's front-mounted roller-crimper,
and they were immediately interested. After consulting with
TRI farm manager Jeff Moyer on the details and obtaining a
small grant from Michigan's Project GREEEN (Generating Research
and Extension to meet Environmental and Economic Needs www.greeen.msu.edu),
Mutch had his technicians build a roller in spring 2004 and
immediately put it to work.
As luck would have it, the research station had some cover
crop trial plots that had been established in late summer
2003, including plots of hairy vetch (sown at a rate of 45
pounds an acre on Aug. 15) and rye (sown at 2 bu/ac on Sept.
9). Mutch and his team set up a randomized complete block
design with four replications of two treatments, one for the
hairy vetch and for the rye. Both the rye and the vetch plots
were rolled down on June 4, 2004; four days later, soybeans
were drilled on seven-and-a-half-inch rows at 180,000 seeds/acre
(the bean variety was Pioneer 92M10). There were no additional
fertility amendments and nor any supplementary weed control.
The beans were harvested on Oct. 7. Yields were excellent
in both treatments, although they were slightly higher in
the rye (62 bu/ac) than in the vetch (58 bu/ac).
As with any new system, there were some hiccups. Although
the Michigan team initially planned to front-mount the roller,
as the Rodale farm team has done, they had so much trouble
sourcing a front-mounted three-point hitch that they eventually
decided to rear-mount the implement and resign themselves
to a two-pass rather than a one-pass system. (They even tried
driving backwards so that the roller could roll ahead of the
tractor tires, but they quickly abandoned that strategy as
impractical.) "In organics you might have ten trips across
the field," says Mutch. "We had two."
Mutch's team also experimented in 2004 with some spring-seeded
cover crops, including oilseed, radish and oats, but didn't
have much success with them. For 2005, they'll be testing
eight treatments, including wheat and triticale as cover crops
but continuing, for now, to work exclusively with soybeans
as a primary crop. ("Corn is more of a challenge because
we plant earlier," he says.) Although with their roller
already in hand the Michigan researchers have a jump on the
other participants in The Rodale Institute's No-Till Plus
Project, Mutch says he plans to stay on schedule with the
rest of the group by establishing on-farm test fields of cover
crops in the fall of this year and beginning data collection
in collaboration with participating farmers next year. "Our
hope is to use the data from this year to give the farmers
good recommendations for 2006," he explains.
On to Illinois
While Mutch is continuing his organic no-till trials this
season in Michigan, he's also had a hand in expanding the
system further west. In 2003 and 2004, weed ecologist Dr.
Adam Davis held a post-doctoral position at the Kellogg Biological
Station and worked with Mutch on the organic no-till trial
among other projects. Because the system showed such promise,
Mutch and Davis had a second unit built and delivered to the
USDA-ARS Invasive Weed Management Unit in Urbana, Ill., when
Davis accepted the position there.
"Organic no-till is the holy grail, and this is such
a great tool," says Davis enthusiastically. "From
early on we were pretty excited to see what it was going to
do. When I came down here [to Illinois] I knew it was work
that I wanted to expand on."
Davis plans to replicate the Michigan system, drilling soybeans
into rolled-down rye and vetch covers. Whereas Mutch's work
focused exclusively on organic no-till, Davis's research will
include both organic and low-input methods. "I'm looking
across the spectrum from purely organic to someone who is
going to use [the roller] along with other tools," he
explains. Within each cover crop treatment there will be a
zero-herbicide treatment, a half-rate herbicide treatment,
and a full-rate herbicide treatment. (In future years, Davis
says, he may add treatments to test even lower herbicide rates,
like one-quarter or one-third.)
As a weed scientist, Davis also plans to investigate the
underlying ecological issues suggested by the use of the cover-crop/no-till
system as a weed management tool. As he puts it, "I'm
also trying to ask the why questions: If it is suppressing
the weeds, then what's the mechanism by which that's happening?
So we'll be measuring light infiltration, soil moisture, soil
temperature and phytotoxicity from the cover crop residues
both pre- and post-rolling and pre- and post- herbicide applications."
In addition, Davis will work with an entomologist and a pathologist
to begin looking at how low-input no-till interacts with pest
and disease factors.
Like the Michigan group, Davis's team is still figuring out
how best to manage the cover crops within the new system.
This spring they rolled both the rye and the vetch in the
first week of May, then rolled the vetch a second time on
May 18 because it hadn’t gone down completely. (The
rye went down well, even though they had a thick, six foot-tall
stand to contend with.) "We had a really dry fall here
and didn't get a very good stand of vetch," he says.
"This year we're going to plant the vetch earlier, maybe
as early as mid-August, to make sure we get adequate moisture
to germinate it." Despite the dry weather, Davis reports
that soil moisture in the cover cropped plots appeared to
be similar or perhaps even better than in the bare-ground
Part of Davis's learning curve, naturally, has to do with
adjusting to different soil conditions—exactly the process
farmers would go through in adapting the roller technology
to their individual farms. The silty clay loams at the Illinois
research station are much heavier than the coarse sandy loams
at the Kellogg Biological Station, Davis says, which means
that—especially in dry conditions—a heavier roller
is needed to get the same ground penetration with the crimping
fins. "At first it seemed like the roller was bouncing—it
worked better after we filled it with water," he says.
"It made me wonder whether a larger diameter roller wouldn't
work better [in these conditions].
"Unfortunately, with just two different soil types"—at
the Michigan and Illinois research stations—"we
probably won't be able to develop any general rules for matching
roller methods to soil conditions," Davis continues.
But with cover-crop roller testing now going forward in at
least four states and scheduled to begin in half-a-dozen more,
the formulation of such guidelines is surely not far off.
Another strategy Davis brought with him from Michigan has
to do with research methods that foreground farmer involvement.
Although the Agricultural Research Service has no formal extension
mission (in theory, ARS researchers are supposed to be fed
research problems by the land-grants and then feed solutions
back for dissemination through university extension networks),
Davis says, there's still room for interaction. Since arriving
in Illinois last August he's been eagerly forging links with
local farmers. "I work with farmers because I like working
with farmers," he says, "and because farmers have
great ideas for research questions."
|"I work with farmers because
I like working with farmers," says ARS weed ecologist
Adam Davis, "and because farmers have great ideas
for research questions."
As an example of that methodology, Mutch and Davis worked
together on an MSU Extension Bulletin on integrated weed management
that relied heavily—and intentionally—on farmer
input. Davis, Mutch, and three other Michigan State colleagues
assembled a group of a dozen successful Michigan farmers,
half of them organic and half conventional, to talk about
non-chemical ways of managing weeds. "We spent four,
eight-hour days generating content, basically doing a brain-download
from the farmers, asking them, 'What do you use? What do you
wish were around that isn't? What have you heard about but
need more information on?'"
Davis then spent eight months following up on those leads,
searching through journal articles and other scientific publications
to gather the latest, best information on weed management,
broadly conceived, and then pulling it all together in an
accessible format. The result is a 120-page, full-color book
Weed Management: "One Year's Seeding…"
and featuring a wealth of practical, innovative ideas and
"A project like that had been a dream of mine for a
while," Davis reflects. "One of my frustrations
as a student and a researcher is all the good information
that gets locked away in journals and in libraries,"
unavailable to farmers and even to extension personnel. The
situation is exacerbated by shrinking extension budgets, which
force agents to serve wider areas and broader farmer constituencies.
"I look at my extension friends and realize that they
just don't have time to go to the primary material,"
Another of Davis's goals was to highlight some of "the
truly excellent work that my mentor, [Iowa State University
weed ecologist] Matt Liebman, has done. His textbook, Ecological
Management of Agricultural Weeds, is one of my bibles.
There are lots of great [weed management] stories in there,
but it's not something a farmer is going to pick up at the
end of the day." In a sense, Davis says, One
Year's Seeding is "a comic book version of that"—one
that's heavier on the tools and includes lots of pictures
A final objective was to tap farmer expertise in a state
that today boasts significant numbers of successful, medium-to-large
scale organic farmers, particularly in the center of the state
and in the "thumb" of the Michigan mitten, according
to Dale Mutch. "We've got five or six farmers with 2500-acre
organic operations," he notes. "These are some very
experienced, high-level producers" with a lot to contribute
to their fellow producers in Michigan and elsewhere.
IWM: Integrated weed management
The Rodale Institute's organic no-till cover crop roller
is featured in the One Year's Seeding book as an example of
a weed management strategy that goes hand in hand with soil
improvement. But it and other strategies described there also
reflect a larger revolution taking place within the discipline
of weed science, Davis says. On the one hand, the rise of
genetically engineered herbicide-tolerant crops like Roundup-Ready
soybeans has left a previous generation of chemically oriented
weed scientists feeling like they've been made redundant.
On the other hand, that reorientation has opened up an opportunity
for a total rethinking of the possibilities of weed research.
And a new generation of weed scientists, trained in ecological
principles and responsive to the needs of organic and sustainable
farmers, is rising to that opportunity.
"In the 'eighties and even into the early 'nineties,
weed management meant thresholds," Davis explains—the
idea of weighing the expense of weed impacts via yield losses
versus the expense of herbicide applications to reduce those
impacts. Unfortunately, "In most cases, when the analysis
was done the actual threshold level was so low that you just
had to spray all the time."
The new weed science—as pioneered by Liebman at Iowa
State, Dr. David Mortensen at Penn State and many others—adopts
what Liebman has dubbed the "many little hammers"
approach—marshalling a wide variety of weed management
methods that together can weaken and reduce weed populations
over time. The ultimate goal, Davis argues, is to assemble
a truly integrated, "multi-tactic weed management system"
including everything from improved mechanical implements (like
more flexible cultivators) to biological management strategies
(like protecting insects that eat weed seeds) to microbiological
effects (like encouraging microbes that hasten weed seed decay).
In contrast to technologies like Roundup Ready, integrated
weed management seeks to improve farmers' bottom line by widening
their skills and knowledge, rather than by inviting them to
buy expensive patented inputs. "Farmers have made a Faustian
bargain with the input suppliers," Davis observes. "They're
accepting pay as heavy equipment operators rather than as
ecological system managers. I think that's sad for a couple
of reasons, first because they're never going to make a good
living doing that, and second because it doesn't seem like
a very interesting way to farm.
"I look at [integrated weed management] as a way of
doing an end-run around the input suppliers. You ought to
be paying yourself for being a good manager rather than paying
someone else to supply you with inputs."