| 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.
|
