Technological innovation has brought many advancements to agriculture. The incorporation of chemical fertilizers, mechanization, and biotechnology has transformed the way we grow food. Interestingly, there is one method that in essence remained the same: tilling. Conventional agriculture fostered the idea of ploughing as a must, as it was considered by far the best way of treating the soil. But the alarming rates of soil erosion related to conventional agriculture practices have made us reconsider this practice in the form of no-till farming.
“No-till” or “zero till” agricultural systems utilize a combination of herbicides and specialized tools to plant corps without having to disturb the soil by tilling. The systems have shown promising results. This extreme approach to till reduction has two school of thought. One of them focuses only in getting rid of tillage, while the other involves crop management strategies. The latter one, called conservation agriculture, includes crop rotation, permanent soil cover, and minimum soil disturbance (much like no-till).
Pedro Cisneros, professor of Agronomy at the University of Cuenca, says no-till farming is “The climax of agriculture. (…) The farmers that have achieved it have done so because they have handled their soil in a such a way that it no longer requires tilling”.
He is very aware of the catastrophic effects of tilling. “If you plow the soil, in two or three plow cycles, all the organic matter will be consumed and the soil will mineralize”. Such soil, compacted by the machinery, ends up exposed to erosion. It is said that water and wind erosion generate a loss of 1.7 billion tons of farmland soil around the world every year.
But that’s not the whole story.
Research shows that the erosion rate is much faster than the rate at which soils rebuilds. Under plow-based agriculture, producing one inch of soil could take up to 1,500 years, while one inch of soil erosion could take only centuries. In other words, we need urgent measures to stop this from happening.
It is widely known that no-till reduces run-off drastically. It has proven to decrease soil erosion in a stunning 98%, but there are important changes that farmers will have to consider. Professor Cisneros says that “You need specialized machinery like a stubble shredder, special seed drills, and machinery that can incorporate fertilizer to the soil in a less invasive way”. This would translate in an initial high investment. Though, saving in fuel and labour can compensate for that.
Conventional till practices need 6 gallons/acre per year, while no-till uses less than 2 gallons/acre per year. A farmer could reduce fuel consumption (4,160 gallons per year), plus reduce labor costs, to generate savings of around $10,500 annually. Adding to that, carbon sequestration and healthy soils are other benefits from this type of agriculture.
Unfortunately, some practices involve the use of herbicides, creating the misconception that no-till farming uses more chemicals. Professor Cisneros says that utilizing these applications, along with planting cover crops, can help reduce inputs. “Keeping the residue from the last crop has its benefits. It prevents water evaporation, allowing us to decrease the consumption of this important resource”. This would lead to a reduction in the use of agrochemicals, without sacrificing production.
In spite of these conditions, no-till systems covered just 7% of cropland around the world in 2004. Most of that being in the United States, Brazil, Canada and Argentina. For a practice that has been around since the 1930s. It is shocking that it has barely caught on in other continents. Though the cost of transitioning to no-till is an important factor.
Professor Cisneros says this could take some time. “If you have soil that doesn’t have the ideal conditions for zero till. The transition period will be given by the inputs that the soil will receive (…). If your soil is contaminated with herbicides, until the microorganisms get restored, it will take some time”. A meta-analysis of scientific research showed that this could go up to 10 or 11 years, and that the performance of no-till is context-dependent. This means that in arid regions it has shown to increase yields, while in tropical latitudes it has done the opposite.
The debate is on. There is plenty of research in this field, which has been developing for many years. But no clear consensus from farmers. With such imminent threats like climate change and alarming rates of soil erosion, is up to governmental institutions along with researchers to decide where to promote no-till farming. It will be important to approach the issue with care, and support farmers during the transition process.
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