Posted June 2, 2005:"Maybe
we got lucky, but it worked beautifully. Weed control was excellent."
how 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 are."
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 Systems.)
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
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 control plots.
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 titled Integrated
Weed Management: "One Year's Seeding…"
and featuring a wealth of practical, innovative ideas and recommendations.
"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 and graphics.
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."