No-till Farming Can Reduce Climate Impact by 30%, But Is It Perfect?
Around 26% of all greenhouse gas emissions in the world come from agriculture. The key factors are tractor exhausts, methane from cattle and fertilizers that produce nitrous oxide. Yet, there is also a less obvious contributor — tilling.
When soil is broken up, it releases carbon, and microbes convert it into CO2. Tilling, it turns out, is one of the many controversial technologies invented by humanity, you can see here for more. A study released in 2021 shows that no-till farming could reduce emissions of three greenhouse gases (carbon dioxide, methane, and nitrous oxide) by up to 30%! However, this method has its caveats.
What Is No-till Farming?
What if farmers avoided ploughing before sowing crops? This alternative method involves planting seeds in drilled holes instead of disturbing soils. No-till agriculture has already gained traction on both sides of the Atlantic. Instead of using a variety of equipment for tilling, harrowing, sewing and firming, you need a single machine to drill seed holes in one go.
Why No Tilling Works
Conventional methods create big air pockets. With no-till agriculture, these pockets are smaller, which is why less CO₂ is released. At the same time, the soil has enough pores to drain properly and allow roots to reach the water. Another reason why more carbon is stored inside is that decomposed plants stay buried.
The origins of the method can be traced back to the 1930s. The American Dust Bowl, a period of drought and severe dust storms, may have occurred due to tillage. This theory was proposed by agronomist Edward Faulkner who said that “no one has ever advanced a scientific reason for ploughing.” But is no-till farming ideal?
Biggest Concerns
The biggest obstacle to wide adoption is the initial cost of direct drilling machines. Some farmers are concerned that yield may decrease compared to old methods. This is possible in the beginning as seeds adapt to harder, uncultivated soil with less oxygen.
Advantages of No-till Farming
Research shows that roots and earthworms eventually restore a natural structure. Not tilling the soil brings multiple benefits:
- Less Fuel and Labor
Ploughing is the most fuel-intensive process. Farmers can save thousands of dollars per season. They also pay less for labour.
- Less Soil Erosion
As tilled soil is loosened, it is more susceptible to water and wind erosion. Leftover plant material like roots and crop residues act as a shield against rain and wind.
- Reduced Herbicide Runoff
As untilled soil holds together better, herbicides and pesticides do not move.
- Moisture Conservation
The no-till method is particularly beneficial for dry areas where moisture conservation is vital. The stronger the erosion, the more moisture evaporates from the soil. If it is tilled, it is completely exposed. Heat absorption is particularly fast for dark, mixed, tilled soils.
- Higher Yields
This advantage takes some time to materialize. Studies show that this method eventually boosts yield.
- Improved Soil Biology
Tilling kills earthworms and other life forms, which disrupts the soil biosphere and prevents it from being self-sustaining. If farmers let these organisms live and thrive, they make the soil fertile and healthy.
- Reduced Compaction
This may seem counterintuitive, but untilled paddocks have less soil compaction. This is possible thanks to earthworms and general improvements to soil biology. Crop residues reinforce soils.
Disadvantages of No-till Farming
Even the most ardent proponents of no-till farming cannot deny its challenges. We have already mentioned the upfront costs related to the purchase of new machinery. There are other downsides, too:
- It Takes Time
No-till farming does not bring immediate effects. Soil may need several seasons to fully recover and yield as much as before.
- Weed Problems
Farmers have to use more herbicides to keep weeds at bay. What’s more, they deal with a wider weed spectrum.
- Insects
Tilling removes different parasites and other harmful organisms. Without it, farmers have to resort to other solutions, such as spraying.
- Longer-Term Crop Rotation Plans
This should be the least of all concerns. Farmers should plan long-term crop rotation to boost fertility on untilled paddocks.
- Nutrient Stratification
Different nutrients in soil move in different ways. For example, zinc and phosphorus are mostly static. When soil is broken up, nutrients are distributed more evenly.
Final Word
No-till farming has its pros and cons, but the environmental benefits are clear. In addition to reducing the amount of CO2, this method limits the release of methane and nitrous oxide. The biggest positive changes have been observed on farms where this method has been used for 15 years on average.
