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August 2015
ON FARM LEVEL
Conservation agriculture
Crop rotation / Maximum soil cover
SOIL REFORM
– renewable versus sustainable agriculture
S
ince the dawn of man there was a
continuous struggle to secure a
steady food supply. As the cen-
turies rolled past, modern man
invented implements to help create areas
where mass production could be done and
as the world population grew, more and
more natural vegetation was turned into
cultivated fields.
We have reached the maximum land area
for production purposes or have at the
very least, come close to it. This raises the
question: “How do we feed an ever grow-
ing local and world population with the
land we have available at present?” The
simple answer is soil reform.
To understand how simple this answer
is, we have to understand the problems
we caused and how to turn them around.
Prof Rattan Lal, director of the Ohio State
University’s Carbon Management and
Sequestration Centre, has done extensive
research on carbon, the building block of
all living things. He concluded that the
world’s soils have lost up to 80 billion tons
of carbon through our cultivation practi-
ces. In certain areas the loss is nearly 80%.
The figures are staggering, but you may ask
why it is so important for our soil to have
carbon in them?
Soil is not just a substrate that keeps
our crops from falling over; it is a living,
breathing organism for which carbon is
the energy source. With the onset of tillage
implements we have managed to lower
our soil’s natural carbon content to below
0,5% in many cases.
We have literally worked the soil to death
and still expect to keep producing enough
crops. Our soils have lost the potential to
support the crops’ needs. To sustain our
production we had to rely on more and
more artificial means of feeding our crops.
The old way of tilling the soil to fight
weeds and preparing a smooth, even
seedbed has left our fields uncovered,
exposed to the sun (no way to harvest
water) and devoid of material to feed the
life within the soil. Since the introduction
of no-till in the 1970s and the subsequent
development of conservation agriculture as
a method of production, we have manag-
ed to turn this picture around. Across the
world, scientists and producers have shown
the benefits in converting to conservation
agriculture.
The Western Cape Provincial Department
of Agriculture has been running long-term
crop rotation trials based on the corner-
stones of conservation agriculture (CA),
namely crop rotation, maximum soil cover
and minimum soil disturbance, for a period
of 20 years (following in the footsteps of
pioneer producers in the province). Data
from the trials clearly illustrates the sustain-
ability of the practice within the different
cropping systems tested.
This is all fine and dandy, but do we want
to be sustainable in our production or do
we want it to be more than just sustain-
able. In this instance we agree with the
views of Dr Dwayne Beck. He manages
the research facility called Dakota Lakes
Research Farm in South Dakota, USA,
which came into operation in 1989.
The entire facility has always been managed
using true conservation agriculture tech-
niques (continuous low-disturbance no-till
and diverse rotations) since its inception.
The farm is both a research and produc-tion
unit and the research is aimed at improving
not only the conservation side of farming
methods, but also making sure that the
practices are maximising the profits.
Dr Beck is the one who planted the seed
of agriculture being renewable. He hates
the word sustainable, because it indicates
maintaining the status quo. He strives
towards the idea of making agriculture re-
newable and not just a mining operation
such as the gold and oil industry. How do
we achieve this? The simple answer is to
look at nature.
Nature aims for diversity. When last have
you walked in nature where man has not
disturbed anything? Did you see any weeds?
Why not? The answer is diversity. We took
diversity away in our cropping systems
by cultivating a field and planting a single
crop with a single root system on it.
The result was we had to start fighting
weeds coming into the monoculture. This
caused its own headaches with the onset
of herbicide resistance. Weeds are nature
trying to create diversity. CA helped im-
prove the situation through the rotation
of different crops, but is still lacking great
diversity.
Coming back to Dr Beck and his philoso-
phy, the aim is to change our cropping
systems in such a way that we are mimick-
ing nature and the natural cycles. The
research done at Dakota Lakes and other
research stations has shown the benefit
of including cover crops as part of this
simulation of the natural diversity in our
cropping systems.
The introduction of diversity improved the
health of the soil which in turn improved
yields and lowered artificial input costs.
During a recent visit to the Dakotas we met
with various producers who have turned
their farms around and are reaping the
benefits of their soil reform.
Do yourself a favour and read Gabe Brown’s
story (one glaring example of what is
achievable). The sustainable agriculture
magazine
Acres
, based in the USA, pu-
blished an in-depth interview with Brown
in the article called “Diversity is king” – you
can alternatively
his name.
David Montgomery, a geologist by trade,
wrote a book called “Dirt – the erosion of
civilisations” in which he relates his re-
search on the demise of ancient civilisa-
tions of Neolithic Europe, Classical Greece,
Rome, the Southern United States, and
Central America.
Erosion of their agricultural soil played a
large role in the demise of these civilisations.
We have to ensure that our agriculture is
renewable, not just sustainable and to be
able to achieve this we have to reform our
soils to a living, breathing organism.
JOHANN STRAUSS,
Western Cape Department of Agriculture, Forestry and Fisheries