Making the Switch
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Rotations have been called
the most
important management tool in organic systems. Research at this
long- term systems trial at the University of California-
Davis points to starting a rotation with crops
that require less nitrogen.
–Photo courtesy of University of California-Davis |
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Fred Kirschenmann, a North Dakota farmer and a long- time advocate
of sustainable farming systems, gives this advice in the foreword
to Cereal-Legume Cropping Systems, a book for farmers who
are exploring switching to sustainable production methods.
"In switching from one system to another, it is extremely important to
remember that what one is doing is switching systems and not changing technologies.
Many farmers have experienced severe unnecessary losses in making the switch
because they failed to appreciate the difference.
"Making this switch is not simply a matter of substituting green manure
for synthetic fertilizers or substituting organic fertilizers for conventional
ones. Nor is it primarily substituting botanical pesticides for 'toxic' ones.
Making the switch is a matter of slowly backing out of one system of farming
(that relies heavily on off-farm inputs) and slowly introducing another system
of farming (that relies heavily on comprehending and using nature's cycles).
"Effective use of on-site nutrient cycles as the primary source of fertility
requires good organic matter, a crumbly soil structure, minimum compaction and
high levels of biological activity.
"Effective pest control with reduced or no pesticide use also takes time.
It takes time to break the pest cycles that have become established under monocrop
management. Good pest control with fewer off-farm inputs requires a thorough
understanding of the natural cycles of the weeds, insect pests, and diseases
that have established themselves on your farm and then determining what crops
and practices are most effective in interrupting those cycles."
Nancy Creamer, a leader of the North Carolina State University organic transition
experiment comparing a range of organic systems, has benefited from the cumulative
knowledge gained from the last two decades of organic farming research. Based
on past research results, Creamer and her colleagues started their rotation
with soybeans instead of corn and applied principles of organic weed management
to achieve relatively weed-free fields. "It's possible that it's easier
to farm organically now, given the cumulative experience that has been gained
by farmers over the years," said Creamer.
By designing research based on results from earlier studies, Creamer and others
have shown that is possible to make the transition with minimal production losses.
By preparing the land, building soil, focusing on the right crops and rotation,
and not putting too much acreage or too many animals into production, farmers
can minimize what has come to be known as the "transition effect."
Creamer's study, for example, showed that with good weed management, soybean
yields can equal those of conventional beans during the first year of a transition.
How to Get Certified
USDA accredits state, private and foreign organizations
to become "certifying agents." Those agents certify
that a farmer's production and handling practices meet the
national standards.
To initiate the process of certification, the
following information must be submitted to an accredited certifying
agent:
Type
of operation.
History
of substances applied to land for the previous three years.
Organic
products being grown, raised or processed.
An
organic plan, which includes practices and substances used
in production.
This plan should also detail any monitoring
practices that will be used to verify that the production
system will be organic, including the record-keeping system,
and how to prevent co-mingling of organic and non-organic
products and contact of products with prohibited substances.
You will also need to evaluate and prepare a
description of the physical barriers and buffers on your property
that separate your operation from conventional neighbors.
After reviewing the application, if the certifying
agent determines you are eligible, a qualified inspector will
schedule a visit for an on-site inspection. If the application
and inspection report show compliance with the requirements,
certification will be granted. Once certified, you must re-apply
for certification every year, and will also be assessed a
certification fee of a few hundred dollars each year. Many
states currently have cost share programs to offset certification
fees. (Contact your local certifier for more information and
see "Economic Assistance"). |
Management Strategies
Rotations. Start by deciding how to build your rotation, as this is
the most important management tool in an organic system. Your biggest challenges
likely will be weeds and nitrogen fertility, so think carefully about how to
balance those constraints with maintaining a high-value crop.
Grass/legume mixtures provide good cover and supply nitrogen, but if your soils
are low in organic matter, you may need to incorporate the mixtures instead
of cutting them for hay. Research cash crop alternatives that will help steady
your bottom line. At the Rodale Institute, a five-year rotation was cut to three
years to get more high-value cash crops and to allow the grass/ legume mixture
to be used for improving soil fertility.
Mary Howell Martens, an organic farmer from Penn Yan, N.Y., recommends striving
for balance between maintaining soil health and producing economically profitable
yields. "One of the problems we've seen [is farmers] putting the whole
farm into the most profitable organic crop every year. With no rotation, the
yields go to pieces," she said, when interviewed for the SARE-funded educational
video, "Organic Grain: Another Way."
"The crop mix that we have developed maintains our soil health and yields
and also gives us a fairly profitable operation. But the overriding consideration
is: What does this field need? We do put in some crops that are not particularly
profitable, but then they're being rotated with the crops that make us the best
income."
Begin with cash crops that require less nitrogen and can be effectively managed
to control weeds. Many studies have shown that, with proper weed management,
soybeans can be planted in the first year of a transition with no declines in
yields. Corn, on the other hand, is not a good transition crop because it requires
a lot of nitrogen and more weed management.
However, once the system is established, organic corn can be grown quite successfully,
said Kathleen Delate, an Iowa State University organic researcher. Her studies
show that within three years of the transition, organic corn can produce as
well as conventional corn.
Avoid consecutive years of row crops to prevent weed outbreaks and maintain
system productivity. University of Minnesota researchers and a dozen
or so Minnesota farmers collaborating on a SARE project found that
avoiding consecutive years of row cropping during the conversion
to organic production could prevent weed outbreaks and maintain
system productivity. The experiment, which examined the effect of
crop sequence, showed that in the third year of production, the
organic systems where corn or soybeans had been preceded by one
to two years of small grain/forage legume versus a row crop had
lower weed incidence and higher yields by the third year. This suggests
that you should avoid planting two row crops in sequence in the
transition
Other considerations for the rotation:
Does
the rotation match the crop needs for fertility? Try to have crops
with differing root depths so they can access different nutrient
zones.
Does
the rotation have sufficient diversity so that risks will be minimized?
Does
it provide weed control?
Take advantage of mixtures and niches such as the combination of
sorghum-sudangrass/lablab/cowpea planted in early summer following
tomatoes and preceding corn in a California experiment.
"With a nitrophilic crop like corn following tomatoes, it's
important to have a mixture that's building the soil," said
Steve Temple, one of the researchers. The mixture, he continued,
is designed for multiple functions:
The
sorghum-sudangrass germinates quickly in the heat and takes up
residual nitrogen. It also shades out late summer weeds.
The
cowpea, which fixes its own nitrogen, grows productively alongside
the sorghum-sudangrass.
When
the sorghum-sudangrass dies back in early fall, the lablab, also
a legume, emerges, so that by December, when all three species
have winter-killed, the dense mass of cover contains fixed and
recycled nitrogen.
With
all the nitrogen accumulated and fixed in the fall, and stored
in the vegetative biomass over winter, you don't have to wait
for spring growth of the cover crops. The dense mixture can be
plowed under and the crops planted as soon as the ground is ready.
Soils. Building soil organic matter and improving
soil quality is often cited as the most critical step for a successful
conversion to organic farming.
It
may take three to five years for the soil to improve, depending
on the condition of the soil, so start adding manure or composts
and finding other sources of organic amendments as soon as possible.
Balance
production, soil building and conservation. Good crop rotations
that include cover crops and animal wastes help build soil organic
matter.
Do research
and start experimenting. Reading a book on compost, "made
me realize I should justdo things instead of figuring out the
technical parts," said John Vollmer. (See Building Soils
for Better Crops in "Resources")
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