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  • From: "TradingPostPaul" <tradingpost@riseup.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] Managing Cover Crops on a Small Scale No-till Farm
  • Date: Mon, 01 Jan 2007 12:06:37 -0700


Managing Cover Crops on a Small Scale No-till Farm
http://www.certifiedorganic.bc.ca/rcbtoa/training/soil-article2.htm
By Chris Wells. Reprinted with author's permission. First published in the
Sept 2004 volume of Compost for the Mind, the bi-monthly newsletter of
SIOPA, IOPA, and ING.


I tend to talk a lot about no-till soil management in a casual way. But it
seems that I often get less than casual reactions from people when I do.
One question I often get is in dealing with cover crops and turning them
in. Discussing no-till farming in relation to cover corps is a great way to
communicate the principles of no-till farming, as cover crops likely post
the biggest challenge to the no-till concept. I would like to take you
through the process I use to deal with cover crops and carry that on to
give you a look at the life-cycle of a no-till farming system. But first, a
short introduction to no-till farming.

No-till farming and gardening are certainly not new concepts. From Patricia
Lanza's Lasagne Gardening (Rodale Press) and Emilia Hazelip's concept of
the "Synergistic Vegetable Garden" there are many styles of no-till
gardening. And in terms of farming, Masanobu Fukuoka and his famous books:
The One-Straw Revolution and The Natural Way of Farming lay down some
unique techniques for larger scale no-till farming. These agricultural
revolutionaries offer great insight into no-till farming, but why do they
do it?

No till farming is seen as a gentler way of managing soil quality. Emilia
Hazelip's methods are similar to what we would see in a forest, where
nature continuously grows and dies and returns everything back to the soil.
Both Hazelip and Lanza tout mulching as being one of the keys to effective
no-till soil management. Mulching controls weed growth, retains water in
the soil, adds nutrients as the mulch decomposes, and creates soil layers
that are mixed by the movement of soil dwelling organisms.

Much no-till farming is also a direct protest to fossil fuel driven means
of producing food. This means using heavy machinery and tools that require
immense amounts of energy to construct, to run, and to dispose of. Such
methods are hardly sustainable for long and can have many negative effects
on soil quality. There are three major damaging effects that tilling can
have on soil.

One major effect of tilling is damage to soil structure. Improper use of
roto-tilling implements can do severe damage to a farm.s soil structure,
sometimes with irreversible effects. Tilling the soil when it is too wet or
too dry can cause the soil to become either clumpy or turn it into a
powder. And although many farmers are quite aware of this fact, they often
times have no choice but to till in order to establish their crops in time
with the seasons.

The second major effect is compaction. While proper tilling and tractor use
can greatly minimize compaction, in the hurried pace that is the reality on
most farms, it is often easy to overlook that which you cannot see six
inches below the soil's surface. While tilling may loosen the top six
inches of soil and create a seemingly good quality soil, it can severely
compact the subsoil and create major problems for root growth, water
drainage and nutrient uptake. Many farmers are recognizing this fact and
are adjusting their tilling practices, using methods such as shallow
tilling, minimized tilling and using alternative tools like a spading
machine or a good old garden fork instead of a roto-tiller to reduce these
effects.

The third effect that tilling has on soil is on the soil food web that
exists within it. Bacteria and fungi create immense networks under the soil
which form symbiotic relationships with plant roots. The most well known
relationship is with legumes and rhizobial bacteria. These bacteria form on
the roots of plants in nodules and help .fix. nitrogen for the plant to
utilize, while "borrowing" carbohydrates from the host plant. A similar
process happens with mycorrhizal fungi and plant roots to help plants
better absorb nutrients and water. Tilling the soil destroys these networks
of bacteria and fungi, preventing them from becoming more established and
thus beneficial to plant growth. This is an important aspect of no-till
systems, especially when dealing with cover crops.

I believe that one of the most important aspects of is the establishment of
permanent growing beds and established paths through out the farm. This
means that one always walks on the paths, and never walks on the growing
beds. This alone will eliminate much compaction, which is one of the
reasons people till . It is often thought that the soil itself compacts
over time and must be tilled to loosen it up, but my experience tells me
otherwise. I can easily thrust a garden fork all the way up to the start of
its handle into beds on my farm that have not been tilled in three years.
Gravity and weather have very little effect on soil compaction in most
cases. This will, however, differ slightly with different soil types. Mid-
and small-scale farmers who till using a tractor can use this concept of
paths and beds as well by ensuring that the tractor tires pulling the
tiller are always in the same position on the paths and therefore never
come in contact with the actual growing areas. The use of established
patheays, coupled with shallow tilling, is an effective way of reducing
damage to the soil structure and to the soil food web.

Establishing permanent beds also makes irrigation installation and
management much easier. Drip lines do not have to be constantly moved, and
there is much less risk of running over irrigation lines with the tiller as
well! Drip lines that are bent often, quickly develop kinks and breaks that
effect their efficiency and proper water distribution.

So, as I mentioned, managing cover crops can be the biggest challenge in no
till farming. But I have a few strategies that have been successful for
me...

First, is my selection of cover crops. As a general rule I do not use grass
cover crops. These are very difficult to kill off without tilling. The
three cover crops that I generally use are buckwheat, winter and field
peas, and calendula. Buckwheat is fast growing and can add a lot of organic
matter to he soil very quickly when it is killed off. It is also easy to
kill off and it decomposes rapidly. Field and winter peas are good nitrogen
fixing crops and are also easily killed off without tilling. And calendula
is great for adding organic matter and a little bit of colour on your
farm.. It is also rather cold hardy and can do very well in a mild winter,
sometimes flowering in December!

Second is how my cover crops are "turned in". I use two methods, one of
which can also be utilized in a tilling system. The first method is a
mulching method, which is contingent on available materials. We.ll use
buckwheat as a first example. When the buckwheat starts to flower, I cut
the crop down with a scythe or weed-eater. I cut the buckwheat down as low
as I can and then lay the cut materials over top of the soil bed and the
buckwheat roots to cover them completely. I then mulch over top of the
chopped buckwheat with compost or straw to finish killing it off. The mulch
prevents light from getting in and allowing the crop to re-grow, and the
high nitrogen content in the fresh cut cover crop causes high biological
activity under the mulch, resulting in the killing of the cover crop.s root
system, which is still in the ground.

The second method is more of a shallow tilling style. After I have cut the
over crop down, I use an action (stirrup) hoe to separate the root from the
top of the plant. This kills the roots almost instantly and only disturbs
the top inch or so of soil. This methods results in faster decomposition of
the cover crop. This method can be used in conjunction with the first
method as well. Once the roots have been cut, then the bed can also be
mulched.

Decomposition takes 2-4 weeks depending on the time of the year, obviously
much longer in spring. If I used compost as a mulch, I can then seed
directly into that compost. If I mulched with straw, I pull the it off the
bed, rake off any remaining debris underneath to smooth out the bed, sow my
seeds, then return the debris to the bed as a light mulch.

So what happens next? Well, I grow a crop! So, lets say we sowed some
winter peas in September, and then mulched them with compost and killed
them off in mid-March of the next year. By mid-April the cover crop is
dead. We then sow some mustard greens into the compost mulch. The mustard
greens are ready to harvest by late May and are removed from the bed.
Compost is applied again and the area is watered (overhead, not drip) for a
few days in a row (e.g. one hour each day). This watering helps the compost
nutrients leach into the soil below and promote the activity of soil
organisms which will move the compost down through the soil. After a few
days of watering we plant bush beans into our new compost.

In mid to late September we remove the bean plants to make room for another
winter cover crop - this time, calendula. When removing the beans, we can
either pull the plants right out of the ground (and possibly hang them to
let seed mature), or we can cut the plant off right at the base. If we pull
the plant right out, we can sow our cover crop immediately afterward with
no additions. If we cut the plant at the base, then we again mulch with
compost and sow the cover crop into the compost right away. Our cover crop
leads us to next spring, and the process can begin again.

So, as you can see, this is not only an effective method of soil
management, it is also an effective method for soil building. The constant
additions of organic matter, even in small amounts, build soil quality
quickly and help significantly in the building of soil structure. The
Organic matter also promotes biological activity which helps results in
more soil food web activity and thus in healthier soil. Still not
convinced? Still feel you need to till to loosen the soil to create a good
seed bed or turn in a cover crop? Well, I have some 20 inch parsnips that
may help change your mind. And while these exact methods may not work for
you, their concepts can be applied in many situations with very positive
results. Go ahead, try it out. All you have to lose is a that vibration
that cuts through your body every time you use a roto-tiller.






  • [Livingontheland] Managing Cover Crops on a Small Scale No-till Farm, TradingPostPaul, 01/01/2007

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