June 16, 2005: In real estate, experts say, there
are three key factors: Location, location, location.
I like to say there are three key factors in sustainable farming:
Rotation, rotation, rotation!
Rotate your crops, rotate your cover crops, and rotate your tillage.
Sounds simple enough, but in practice it takes thought, planning
and a mind open to observation.
I have a friend in Mississippi who says jokingly, “We have
a long term rotation down here—one year of corn, then 99 years
of cotton, then another year of corn.” But that's not exactly
what I have in mind for this discussion.
A few years back I visited some friends in Argentina who were planting
soybeans one fine November day. I asked them what their rotation
was. They responded by asking me what I meant by the question. I
said, “Well, you’re planting soybeans here today, what
was here last year?" They said, “Soybeans.” Like
a fool, I persisted: “And the year before?” By now I’m
sure they thought I was just plain stupid because they said, “SOYBEANS
– it’s a soybean field.”
They had been planting soybeans in that field for over 40 years.
They were experiencing severe problems with insects and weeds. Nature
had responded to the presence of soybeans on an annual basis. The
micro-environment was very predictable, and insects, diseases and
weeds that found that environment to their liking knew where to
find it, year after year.
There are all types of rotations for all types of cropping sequences.
For example, some folks in our area grow agronomic crops (corn,
soybeans, small grains and hay) but also grow vegetables. They often
rotate their vegetable production into and out of various parts
of their farm, confusing insects and taking advantage of “clean
spots” in the rotation where weed management will be less
difficult. For other, smaller-scale growers, a rotation can be as
simple as moving the tomatoes to another part of the garden.
I think the longer the rotation the better. Of course that means
you need to grow a diversity of crops. Here on our farm I’d
like to have a 10-year rotation but 5 to 7 years is more realistic
given the crops we grow. I also like to rotate my cover crops into
All solid rotation plans have some basic principles in common.
First, they all take into consideration the nutritional requirements
of the crop. For example, corn in my rotation is a heavy user of
nitrogen while soybeans will actually fix nitrogen from the air
into the soil. Alfalfa removes phosphorous at a much higher rate
than other crops in my rotation.
Second, a solid rotation should take into account the agronomic
and cultural practices associated with the crop. For example, some
crops are grown as row crops, planted in rows from 15 to 42 inches
apart, while others like oats or wheat are drilled in rows that
are only 7 or 8 inches apart. And others like hay grow in a thick
stand, get mown as a harvest method, and may last several years.
Third, cover crops can be used in the rotation to break weed cycles,
supply nutrients and protect the soil. And finally, a solid rotation
takes tillage into consideration.
Taking a closer look at tillage is as important as any other factor
in your plan. For example, planting winter wheat entails late summer
or early fall tillage, which helps break weed cycles. Consistent
spring tillage encourages annual weeds to sprout and grow. Mixing
up tillage dates can be a big help to your overall weed management
program. There may even be points in the rotation where no tillage
is required to establish a cash crop or cover crop, as with the
no-till roller system I’ve been talking about lately.
While we use several crop rotations on our farm, the one we use
most for agronomic crops goes something like this: CORN –
RYE COVER CROP – OATS – SOYBEANS – RYE , OATS
OR WHEAT – VETCH OR ALFALFA/TIMOTHY – CORN. I also grow
potatoes and pumpkins, substituting them for corn in the rotation.
For vegetables things can get a little trickier due to the large
diversity of crops. We often grow up to 20 different types of vegetables.
The main thing to keep in mind is to separate vegetable families
by time and distance.
The benefits to rotations are many – improved soil health,
easier weed and insect management, and overall improved ecology
of the farm. Add to those the benefit of increased yields and you
have to ask, “Why wouldn’t I have a diverse rotation?”
Email me with your
own rotations or rotation ideas. I’d like to learn more from
you about how you’ve designed your own system so that we can
all improve our farming operations.
From one farm to another,