| With
the first growing season winding down on our No-Till
Plus project, we wanted to find a way to organize what
we’ve all been learning together into an easily accessible
format, one that we can build upon as we learn more. So, we
poured through the reader mail and came up with a list of
frequently asked questions.
What are the major challenges
of a no-till roller system?
What are some of the greatest advantages
of a no-till roller system?
Explain
the no-till roller system’s effect on soil biology.
What about soil compaction?
Will no-till work with conventional row
crops?
Can I no-till roll a weed-infested
field?
Can I use the no-till roller on cover crops
such as Marshall rye or sorghum Sudangrass? What about
red clover before planting a pasture?
Can you explain why timing
is so important when no-till rolling and how this relates
to different types of cover crops?
How do I select the best cover crop(s)
to use if I want to try organic no-till?
Can I use a no-till roller
on a home- or market-garden scale? What about setting
one up for a rototiller or garden tractor?
What is the benefit of rolling the cover
crop instead of simply mowing it down?
NEW! Is
no-till vegetable production possible?
NEW! How
do you sow the cover crop? Is it no-till, too?
NEW! How
can I use the manure and compost in my field without tilling
these amendments in to incorporate them into the soil?
NEW! Will
I have to make any modifications to my seeder in order
to plant into a rolled-down cover crop?
NEW! Is
the no-till roller system compatible with hilly farmland?
What
are the major challenges of a no-till roller system?
Anytime we are asked to learn a new process there are unexpected
challenges to overcome. The no-till into cover crops system
is no different. One of the challenges is matching the cover
crop to the cash crop so that timing and planting date issues
are avoided. For example, we no-till corn into legumes to
take advantage of the free nitrogen. Typically on our farm,
we use hairy vetch as our legume of choice, since it does
well in our climate. However, many of the vetch varieties
seem to flower later than we'd like, often delaying corn
planting till early June. Some of are collaborators are
breeding for earlier maturing varieties to remedy this problem.
Another major challenge is to re-evaluate how you think
about cover crops. They’re no longer “just a
cover crop” but the most important component of your
weed-management strategy and, in some cases, your primary
source of nitrogen. Therefore your success in growing cash
crops is directly dependent upon your ability to consistently
grow excellent stands of cover crops.
And the last challenge has to do with the system itself
and the tools (cover crop rollers and no-till planters)
we use to manage them. Having the right tool for the job,
using it correctly and at the right time to kill the cover
crop, and then setting the planter to plant through the
heavy residue are all key to the success of the system.
What
are some of the greatest advantages of a no-till roller
system?
- Prevents soil erosion.
- Builds organic matter in the soil.
- Minimizes soil disturbance
- Living root systems in soil stimulate microbial activity
including mycorrhizae.
- One-pass system saves time and energy.
- Does not rely on pesticides like conventional no-till
(explain that it’s actually “limited tillage”
and why.
- Creates biomass above and below the ground.
- Conserves water.
- Recycles nutrients.
- Creates channels for water, air and nutrients.
- Increases soil tilth.
- Improves aggregate stability.
Explain
the no-till roller system’s effect on soil biology.
What about soil compaction?
Since our no-till system provides a continuous root zone
(with the noted exception in the next paragraph), we create
a very hospitable environment for the beneficial micro-and
macro organisms that build up the soil and make water, air
and nutrients more available to crop plants. This system
also creates biomass, both above and below the ground, which
adds organic matter that feeds these microbes and stimulates
their activity. Some of the microbes (mycorrhizae fungi)
produce hyphae, microscopic hairs that branch out from the
root system up to 18 feet and produce glomulin, the “Super
Glue” that binds soil particles and increases aggregate
stability. The minimized soil disturbance also helps build
up soil carbon reserves. When you also consider the benefits
of better water infiltration and less erosion, it’s
easy to see how soil health is improved.
As far as soil compaction goes, in our system we only no-till
for two or three years in a row, then we use a plow. So,
in that sense, we are not a true continuous no-till system.
We mix no-till into a plow-till system to take advantage
of both systems to manage weeds and improve soil health.
Also by using this no-till technology in conjunction with
cover crops, we’re able to reduce soil compaction
over the course of our multi-year crop rotation.
Will
no-till work with conventional row crops?
Yes, it works for corn and soybeans as well as with other
traditional wide-row crops. We have made great improvements
in the organic no-till system over the past five years.
These have come in the form of better equipment to manage
cover crops and to plant into them to establish the crop
and suppress the weeds. The improved practice works well
for growing our organic corn and soybeans. These practices
also serve you if you use agricultural chemicals—such
as herbicides or insecticides—by helping you cut down
your use of them.
We are also working across the country to address the
issues of cover crop selection and the related cultural
practices to get the most out of them in terms of the system.
There are now plans
available for our roller and we have partnered with
a local
manufacturer who builds and sells rollers. This is the
tool we designed at The Rodale Institute and have written
about in New Farm (see the
No-Till + Page for more on the roller and no-till research).
With this tool and some planter modifications, the system
has been shown to have great success.
We are in the process of field testing the equipment in
seven regions of the country to gain experience with different
cover crops, different soils, different climates and different
farmers/managers. Within two years, we expect to have that
data to better support farmers who want to move in this
direction.
Can
I no-till roll a weed-infested field?
Not without lots of herbicide. Let me explain what I mean.
Our roller is really designed to work in combination with
cover crops—specific cover crops that are “winter
annuals.” These are crops like hairy vetch, rye, Austrian
winter pea, wheat, barley, etc. And they are all crops that
are generally planted in the fall, live through the winter,
thrive in spring, and finally die back in summer and drop
their seeds.
What our roller does is kill these crops early—once
they have physiologically reproduced, but before the seeds
are ripe. So, in effect, we are working with nature to better
time an event that will happen naturally to suit our need
to grow a crop and protect it from weed pressure. Now, as
for weeds or perennial plants, our roller really won't do
much to kill them. What will happen is that the roller will
physically knock them down, the planter will go through
the mat, and then the weeds will grow back and choke out
the crop. That is why I said you'd need herbicide or tillage
to kill the weeds.
In a conventional no-till system, we use herbicides to
replace tillage to manage weeds. With our system, we use
cover crops to replace tillage or herbicides.
Can
I use the no-till roller on cover crops such as Marshall
rye or sorghum Sudangrass? What about red clover before
planting a pasture?
More than likely, you already have some existing vegetation
where you expect to plant your pasture. The roller we have
designed works to kill “winter-annual” cover
crops by crimping their stems once they have flowered to
create a dense mulch layer that prevents weeds from germinating.
The system is not designed to kill annual or perennial
weeds or ground covers. Therefore, if you have an existing
pasture or weedy areas, it will do very little to help get
a pasture established.
If your land is organic or chemical free, you will need
to perform some sort of tillage activity to establish a
new pasture. If you plan to use a chemical treatment, check
with your county extension agent for the best strategy to
remove what is existing, or knock it back to plant your
pasture mix.
Red clover is a bi-annual and not recommended for this
system. We have seen this year where short rye isn't staying
down like it should. We have rolled barley and wheat in
the past; they were short -strawed varieties and rolled
nicely. Often, a cover crop such as hairy vetch doesn't
look great the day you roll it, but a week later you'll
see it die down (if you waited until it was in full bloom).
Can
you explain why timing is so important when no-till rolling
and how this relates to different types of cover crops?
The biggest issue with timing is that you don’t want
to roll your cover crop too early; this is an all-too-common
mistake. If the cover crop is not at full maturity (as defined
by initiating full reproductive status), it’s going
to come right back to haunt you as a weed. Maturity varies
by cover crop. With hairy vetch, you want to make sure at
least 75 percent of the crop is flowering for a good kill.
There should be immature seed pods at the bottom of the
bloom area. With rye, you’re looking for a “milky
dough” stage in the seed formation, where the seed
pod has the consistency of milky dough or yogurt.
How
do I select the best cover crop(s) to use if I want to try
organic no-till?
Your cover crop and cash crop must be a good match, timing
wise, with respect to your goals and your growing region.
Variables to consider include biomass (how many pounds produced
per acre) and when the cover crop in question comes to maturity.
Hairy vetch is an excellent choice as far as the way it
behaves when rolled down, but it’s not a good match
for the South because it matures too late with respect to
the cash-crop season. Crimson clover is a better choice
for Southern climates, though as you move northward this
cover crop is not able to put on enough biomass for adequate
weed suppression, or for providing adequate nitrogen to
support good yields. While we’ve had great success
planting corn into rolled-down hairy vetch in early June
here in southeastern Pennsylvania, for some farmers this
just isn’t early enough (plant breeders are working
on earlier-maturing varieties of this cover crop with some
level of success). So your choices really depend on a combination
of what will work in your growing region and your own personal
goals. They also depend on the type of cash crop you are
growing.
Soybeans, for instance, being legumes themselves don’t
need a legume as a cover crop. Rye works very well as a
rolled-down cover for this crop. We’re also experimenting
with rye, wheat, oats and barley as possible winter-annual
cover crops suitable for rolling. Many of these grain covers
will work for pumpkins, vine vegetables like cucumbers or
squash, or even string beans.
The goal always needs to be matching the cover crop needs
and expectations to the cash crop in terms of timing (when
is each planted and when does each mature), nutritional
needs (does the cash crop require a legume as a cover),
and water requirements, since some crops like rye tend to
have a high water demand (an important consideration in
arid climates).
Can
I use a no-till roller on a home- or market-garden scale?
What about setting one up for a rototiller or garden tractor?
Our no-till roller is set up to be front-mounted on a tractor
with the seed-planter on the rear for a one-pass system
that saves time and fuel. Of course, the smaller an area
you are planting the less critical these concerns become.
J.I. and Bob Rodale developed their regenerative farming
techniques with the idea that farmers could and should apply
the same care to their fields that organic gardeners apply
to their gardens. Cover crops are certainly an integral
part of a home or market garden as they are any farm, and
the same advantages of rolling them down—namely, providing
a weed-suppressing mulch over a longer period of time—exist
in both environments. Indeed, cover crop rollers can come
in all shapes and sizes; just visit our roller/crimper
gallery and see for yourself You’ll find one mounted
on a large garden tractor; pulling one with a front- or
rear-tine tiller might be a little trickier. However you
could easily design and built one that could be small enough
to pull by hand. The idea is to bend the cover crop plant
over and crimp the stem every 6 to 7 inches along its length.
Any tool that does this has a good chance of being effective.
As for planting vegetable crops, you should be able to
transplant or direct seed into the system depending on what
you want to plant and what cover crops you have available
to you. For example we are direct seeding pumpkins into
hairy vetch. You could also direct seed cucumbers or squash
the same way. Small seeded plants like lettuce or carrots
would be much more difficult but not impossible (lettuce
plugs or seedlings are probably the way to go). If you have
a more sophisticated planter, like a Monosem no-till vacuum
planter you could get the seeds in the ground, but getting
them up through the mulch of the rolled cover crop may be
tough (that’s something we’ve never tried).
Ron Morse, PhD, at Virginia Tech has done quite a bit of
no-till veggies into cover crops as has Jeff Mitchell, PhD,
at the University of California, Davis. Both of these researchers
and several farmer co-operators are successfully no-till
transplanting crops like tomato, eggplant, cabbage, etc.,
into these systems.
What
is the benefit of rolling the cover crop instead of simply
mowing it down?
There are several key differences that occur in the system
when a mowing action is used instead of rolling/crimping.
First, if we use a mower, the cover crop material is cut
into small pieces. This action encourages more rapid decomposition
of the plant material. This is something you don’t
want since you will be depending on the mulching effect
of this plant material to suppress weed germination. The
second problem we’ve experienced is that once the
cover crop is actually severed from the ground and becomes
loose material sitting on the soil surface, it becomes an
impediment to the planter which will simply drag the cover
crop up into piles.
Our roller, on the other hand, is designed to crimp off
the vascular system of the plant stems every seven inches,
effectively killing the cover crop (as long as it’s
in full boom). Leaving the plant attached to the ground
allows the planter to move freely through the field and
slows down the decomposition process.
Is
no-till vegetable production possible?
Yes, you can transplant or direct seed right into a rolled-down
cover crop. Our experience here at The Rodale Institute
is currently limited to direct seeding pumpkins, corn and
soybeans into hairy vetch, a mixture of vetch and oats,
and rye. But others around the country have been working
with other vegetable-crop/cover-crop combinations in organic
no-till systems (see our no till research updates
in the December 2006 issue of New Farm for some
examples).
Ron Morse, PhD, a professor of horticulture at Virginia
Tech, has pioneered research into organic no-till vegetable
production, experimenting with broccoli, potatoes, tomatoes,
cabbage and other vegetables planted into a variety of high-biomass
cover crop mixtures. One of the keys to his success was
the creation in 1990 of a “Sub-Surface Tiller-Transplanter.”
The front component is a durable sub-surface tiller that
prepares a narrow strip of soil, loosening it as deep as
8 inches. Next in line is a no-till transplanter that sets
transplants into the prepared strip. The press wheels of
a double-disk opener ahead of the planting shoe are modified
to close the untilled soil around the plant. Like our work
here on our farm, it’s all about finding—or
making—the right tool for the job. To find out more
about Dr. Morse’s work with organic no-till vegetables,
see the article Organic
no-till for vegetable production?
Jeff Mitchell, PhD, is doing similar work on the research
station at the Kearney Research and Extension Station in
Parlier, California, as well as working directly on growers'
farms in the region. He’s also one of the collaborators
on our No-Till Plus
Project.
How
do you sow the cover crop? Is it no-till, too?
Ours is actually a limited tillage system, as we do till
in the fall to plant the cover crop. We are organic and
we are rotational, so the no-till crop is not continuous
as with conventional no-till.
We have tried no-tilling the cover crops in this system
in the past and found the weed pressure to be too overwhelming.
We do no-till cover crop—say rye into corn or soybean
stubble—in situations where we’ll be plowing
the crop under in the spring; this would then be planted
to spring oats. But in a situation where we’re planting
that cover crop to be rolled for organic no-till, we like
to start with a clean seedbed in the fall. It is very important
to have an excellent stand of whatever cover crop you plant,
since this will be your primary defense against weed seeds
germinating. The same cover may also be your primary source
of nitrogen in the system, making it that much more important
for the cover crop to be well established. Therefore we
take whatever steps we need to in order to ensure a solid
stand of our cover crop.
How
can I use the manure and compost in my field without tilling
these amendments in to incorporate them into the soil?
In our rotation, we typically apply compost to our fields
following wheat or oat harvest. We only do this every five
years, at a rate of 8-10 tons/acre. Then we plow it under
and plant the fall crop.
Compost can be surface applied but typically you will not
gain as much benefit as when you incorporate it. Manure
should be incorporated because you can lose a lot of nitrogen
due to volatilization. Surface-applied compost and manure
are both subject to runoff in the rainy season, though compost
is more stable so this is less of a problem. There are several
new tools on the market to knife-in the manure for no-till
systems, but in our system—where we still incorporate
tillage at some points in the rotation—we apply the
manure ahead of the tillage.
Will
I have to make any modifications to my seeder in order to
plant into a rolled-down cover crop?
Yes, more than likely. You may need to apply more weight
to have the force necessary to cut through the thick rolled-down
mat. The depth of the double-disk openers will also need
to be adjusted in order to adequately cut through the mat
and then into the soil. Oftentimes we find that the seed
furrow that is cut does not close as easily in a no-till
system with all this residue as it does in a tilled system.
Therefore, we upgraded the press wheels on the rear of our
planter from rubber to cast-iron to ensure adequate seed
furrow closing and proper seed-to-soil contact. These considerations
change depending on your soil type; observation and adjustment
are going to be critical to your success.
Is
the no-till roller system compatible with hilly farmland?
Yes, and you’ll still want to be certain that you
farm along the contour of the hill. This may be slightly
more challenging than farming on flat land, but it is certainly
manageable. In fact, reducing tillage on sloping fields
is a great way to preserve and protect your soil. I generally
start my planting operation on the uphill portion of the
field and work my way down slope to allow for any possible
drifting of the tractor due to the gravitational pull of
the equipment. If all goes well, your crops will do just
fine, and not needing to cultivate along the hill will save
you time and extra aggravation.
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