Soil reform - renewable versus sustainable agriculture

August 2015

JOHANN STRAUSS, Western Cape Department of Agriculture, Forestry and Fisheries

Since the dawn of man there was a continuous struggle to secure a steady food supply. As the centuries 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 growing 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 practices. 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 managed 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 cornerstones 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 sustainability 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 sustainable. 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 techniques (continuous low-disturbance no-till and diverse rotations) since its inception. The farm is both a research and production 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 renew able 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 improve the situation through the rotation of different crops, but is still lacking great diversity.

Coming back to Dr Beck and his philosophy, the aim is to change our cropping systems in such a way that we are mimicking 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, published an in-depth interview with Brown in the article called “Diversity is king” – you can alternatively Google his name.

David Montgomery, a geologist by trade, wrote a book called “Dirt – the erosion of civilisations” in which he relates his research on the demise of ancient civilisations 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.

Publication: August 2015

Section: On farm level