"I started farming here in 1958 with my father. I now farm with my son, Terry. We South African farmers often say that farming is hard now, but it was also hard in those years, even though it was for different reasons. Back in the 1960s, one of the goals of crop farmers was to have a nice weed-free seedbed for optimum seed-to-soil contact at planting. The priority was to get maximum seed germination for maximum yield.
To achieve this, farmers used any means possible, including first burning off organic residue and then ploughing and discing the soil. While we were all following these processes, in the back of our minds were the principles we read in books such as Ploughman’s Folly (1951) by Edward Faulkner, that encouraged farmers to begin implementing a more sustainable approach to soil and water management.
However, after the Second World War, there were many millions of tons of nitrates and other chemicals that had originally been intended for bomb production, standing unused. It was discovered that the best way to get rid of these was to use them as fertilisers, herbicides and pesticides in commercial agriculture. Unfortunately, after the war, the rapid adoption of chemical fertilisers worldwide, including in South Africa, led to the misconception that previous good crop management practices, such as crop rotation, were no longer necessary.
At the time, most farmers felt chemical fertilisers were the be-all and end-all for best soil health and maximum crop yields. This meant that by the 1970s, international commercial agriculture was in big trouble because a great deal of arable land was almost totally devoid of important organic matter.
Organic matter and soil cover are the vital foundations of healthy and sustainably productive soil. If it is depleted, only the mineral part of the soil is left. You just have sand, which is easily washed or blown away, and can’t retain moisture. So, in South Africa in the 1980s, the government and some far-sighted farmers began investigating the feasibility of conservation agriculture as a way to significantly reduce erosion and rejuvenate the health and productivity of the country’s arable land by trying to get our soils as close to their virgin state as possible.
But another problem came with the introduction of the four-wheel drive tractor. If used correctly, a four-wheel drive tractor is an amazing tool, but these machines tempt impatient farmers to work their lands when the soil is still too wet. This results in heavy compaction, not only from wheels but also from the use of implements, like ploughs and discs. Desirable soil structure is destroyed. And the more compacted the soil, the less moisture it can take.
Then there was a massive outbreak of the crop disease, diplodia. Farmers immediately blamed no-till as causing and spreading it to conventionally grown maize crops. An investigation found that maize genetics recently introduced into the country did not have the tolerance to diplodia that is common here. No-till was not the cause. But the damage had been done, and most farmers trying out no-till immediately reverted to conventional tillage.
There were still farmers, including myself, who continued to research and trial no-till. Until some time in the 1990s we had to modify conventional tillage planters ourselves to try and turn them into effective no-till planters, without much success. Then one of our pioneer no-till farmers, John Jackson, went to the US and came back with some Yetter coulters that could be used to convert almost any conventional tillage planter into a no-till one.
This revolutionised no-till farming in SA. John Deere began importing dedicated no-till planters in about the mid-1990s. Other agricultural machinery companies soon followed suit. By comparison, the use of conservation agriculture methods here, although having grown significantly in certain parts, still lags far behind many other countries.
Unfortunately, in recent years, many of our farmers and ongoing conservation agriculture trials appear to have lost sight of the fact that these methods should be used for improved soil health and moisture conservation, and therefore for sustainable agricultural production. Instead, the focus of SA conservation agriculture has reverted back to how yields can be maximised.
As a result we’re still exporting most of our arable soils through erosion from lands and into the sea. There’s even been equipment designed to build massive contours to act as buffers against wind and rain erosion. This shows we are treating the symptoms of the problem, not the causes. This is not a sustainable approach. The cause is that often there’s no organic matter left in our soil, and many farmers don’t leave any form of organic cover on the soil surface between cycles.
Instead we should be measuring soil by water erosion, wind erosion, moisture infiltration, crop yields, organic carbon content, humus content, and soil cover – all to determine the success or failure of our conservation practices. Proof of why soil cover and organic matter content are so important is evident when one compares in-field soil quality of conventionally tilled lands against the soil quality of these lands’ headlands.
The headlands, which are almost always covered in some form of plant material and are rich in organic matter, are subject to heavy motorised traffic during the course of the lands being prepared for planting, crops being treated for whatever purpose, and crops being harvested. Yet, when one examines headlands soil, it is often full of life, has good structure, and absorbs and retains moisture well – far more so than the soil of conventionally tilled lands.
When these lands are opened up by a plough, the existing organic matter is exposed to oxygen and therefore rapidly decomposes, releasing carbon dioxide into the atmosphere – which is undesirable. The remnants of this rapidly decomposed organic matter can’t provide soil with desirable properties. Not replacing organic matter exacerbates the problem. Organic matter in soil that isn’t opened up decomposes at a much slower and desirable rate, providing what the soil needs to be healthy. Hence the need for conservation agriculture practices such as no-till.
I’ve been implementing only no-till for many years now. The benefits I’ve experienced as a result have been phenomenal in comparison to conventional tillage. My soil is healthy, productive, and absorbs and retains moisture. Over the years, many scientific conservation agriculture-related trials have been done on my farm and other no-till farms around the country.
The results have proven time and again the necessity for SA to move away from conventional tillage to conservation agriculture practices. Unfortunately, too often these results are only made known to a small group of people before the studies are consigned to gather dust in a storage room. Farmers everywhere need to be told how conservation agriculture can ensure that we conserve our soil so as to continue producing enough food for the world for many generations to come.
Contact Ant Muirhead on 083 378 6751, email [email protected] or visit www.notillclub.com. The views expressed in our weekly opinion piece do not necessarily reflect those of Farmer’s Weekly.