“No-till farming” goes by several names: “do-nothing,” “natural farming,” and others, but they all refer to more or less the same thing: farm practices that don’t involve direct cultivation of soils. There’s no tilling, and the seeds are placed directly into the ground at a specific depth, so called “direct drill” or “direct drilling.”
In modern agriculture, the history of no-till goes back to American agronomist Edward Faulkner, who blamed the American Dust Bowl disaster on conventional tillage itself. He famously claimed that “no one has ever advanced a scientific reason for plowing.”
Since then, no-till farming has grown exponentially, with farmers all around the world adopting the method.
In this article, I’ll go over the advantages and disadvantages of no-till farming.
Advantages of No-Till Farming
The most fuel-intensive work on the farm is ploughing. Ploughs run many centimetres into the soil, and tractors have to pull against all that extra friction. The fuel savings from switching to no-till farming are immediate. Farmers can save thousands of dollars on fuel alone throughout the season.
Ploughing is not only highly energy-intensive, but it takes time. Farmers can save thousands of dollars on labour costs by skipping tillage.
Reduced Soil Erosion
By churning up the soil, tilling exposes it to both wind erosion and water erosion. There are two reasons for this.
Firstly, tilling breaks up and loosens the soil. This makes it more susceptible to erosion on its own. Untilled soil holds together more easily.
Secondly, leftover plant material acts as a barrier. Dead leaves, roots, crop residues, stubble, and other remains from last season provide a kind of shield against rain erosion and wind erosion.
Reduced Herbicide Runoff
Reduced herbicide runoff occurs for the same reason as reduced wind and water erosion. If soils aren’t going anywhere, then neither are your pesticides or herbicides.
Tilling the soil not only increases erosion but also evaporation. Tilled soil is exposed completely. Moisture that would otherwise be trapped in cooler layers below can evaporate. Dark, mixed, tilled soils also absorb heat very easily, which contributes to evaporation.
This means that no-till farming, or even just reducing tillage, can be especially important in dry climates, where moisture conservation is essential.
This benefit of no-till gets less attention than others, but it’s very important. Breaking up the soil by tilling allows trapped carbon to escape into the atmosphere. That’s a loss for two reasons.
Firstly, carbon that’s escaped into the atmosphere contributes to climate change. Keeping that carbon in the soil is a way for agriculture to help fight greenhouse emissions.
Secondly, that carbon is important for soil health and fertility. If organic carbon is escaping into the atmosphere, it can’t contribute to crop health.
The benefits may take a little bit of time to materialise, but over time studies show that no-till generally leads to higher yields. This is important because even farmers who acknowledge the soil benefits can sometimes be wary of no-till farming’s economic effects.
Improved Soil Biology
eAgronom Senior Consultant Simon Boughton often explains to clients that one of the worst things about tillage is that it kills earthworms. Soil is a complex biosphere. Running a plough through it every year never allows that ecosystem to truly become self-sustaining.
In addition to earthworms, paddocks are home to millions of other life forms that participate in making the soil healthy and fertile. Leaving soil untilled allows them to live and thrive.
This may come as a surprise, given that tilling breaks up the soil. Strangely enough, problems that arise from soil compaction are actually less severe on untilled paddocks. This is because of the improvements to soil biology mentioned just above. In the long term, there’s no human tool better at preventing compaction than an earthworm.
A healthy soil ecosystem improves soil pores and actually strengthens soil structure. Crop residues like roots and stubble help soils stay strong without becoming compact. On the other hand, tilling destroys that structure, which makes tilled soil ironically easier to compact with machines.
Disadvantages of No-Till Farming
It’s clear that there are some disadvantages to no-till. Agronomic advice can sometimes feel contradictory in this regard. In an interview, GRDC’s Mark Conyers has stressed that despite advocating the benefits of no-till, agronomists also still recommend tillage as a solution to specific issues.
Even if eAgronom’s own consultants are themselves strong proponents of no-till, there’s no point pretending that it doesn’t come with challenges.
It Takes Time
Switching to no-till is a serious commitment. Tilled paddocks switched to no-till can see yields as low as 5% the next season. Even if the long-term benefits are clear, it can take several seasons before the soil recovers and yields return to normal.
No-till is a different enough process that it often requires major costs upfront in terms of new machinery. Even if it’s possible to spread these costs out over the course of multiple years, it can be an initial hindrance for farmers interested in switching.
Weed Problems and Reliance on Herbicide
Though tillage is damaging to helpful life on the paddock, it also helps keep weeds at bay. Farmers often have to spray more herbicides to deal with this problem.
Changes in the Weed Spectrum
Not only do no-till farms have to deal with more weed problems, but the weed spectrum on no-till paddocks also changes. So it’s not just more weeds, but different kinds as well.
Similarly, not all insect and other life on the paddock is helpful. Tilling can help keep parasites and other harmful creatures at bay. No-till farmers have to find other solutions, often involving more spraying.
No-Till Requires Longer-Term Crop Rotation Plans
With good planning, there’s no reason why this has to be a disadvantage. It’s simply an additional challenge farmers must face. On a no-till paddock, it’s important to make a long term crop rotation plan to maximise fertility.
Nutrients in soil don’t all move in the same way. Phosphorus and zinc are good examples of non-mobile nutrients. By churning the soil, tilling helps keep the nutrient distribution even.
eAgronom’s own, independent agronomists are convinced that no-till is a promising solution to today’s farming challenges. This is why by 2006, 85% of Australian grain was produced under a no-till system. Since then, some farmers have adopted limited tillage in response to specific issues, but it’s clear that reducing tillage as much as possible is a major positive for growers.
Recently, eAgronom sponsored the South Australian No-Till Farmers Association (SANTFA), because we believe farmers need high-quality research and extension to make the most of their no-till paddocks.