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Concentration of CO2 in the Atmosphere

Taking Farming to Net Zero

John Deere autonomous electric tractor. Image uploaded to YouTube.com by John Deere UK IE.

George Harvey

Farming stands out as one of the most important contributors to climate change. The U.S. Environmental Protection Agency lists it as contributing 10% of greenhouse gas (GHG) emissions as of 2020, but this does not tell the whole story (https://bit.ly/31eSEzv). The European Commission lists the five most consequential causes of rising GHG emissions as burning fuel, cutting down forests, livestock farming, nitrogen-based fertilizers, and fluorinated gases. (https://bit.ly/3ldtcTd) Please note that two of these are specific to agriculture, and one of the other three is largely related to agriculture.

Other sources show greater emissions working the land. A story that appeared in Forbes last December, “Why Agriculture’s Greenhouse Gas Emissions Are Almost Always Underestimated,” says that farming and land use may contribute as much as 20% of all GHG emissions (https://bit.ly/34seGka). And an article that appeared in Nature, “One-third of our greenhouse gas emissions come from agriculture,” has a title that says exactly what it means (https://go.nature.com/3gcFqri).

The reasons for the differences lie partly in how emissions are calculated. For example, one of the really significant causes of emissions has to do with the soil and how it is handled. Plants draw down carbon dioxide from the atmosphere. Much of what they turn it into is put underground, in the roots. So plants are potentially great allies. But some calculations have ignored the fact that tilling the soil can cause a complex set of changes that release the carbon back into the atmosphere, destroying the great advantage the plants can provide.

Clearly, farming can be a problem. And just as clearly, when it is understood, farming can be one of our most important tools for reducing emissions. In fact, farming can be carbon negative.

To get a really good understanding of how important this is, we could start with something that recently happened in Australia. Much of the impact with farming has on climate change is through methane that escapes from burping cows and sheep. And much of Australia’s agriculture revolves around cows and sheep. According to a report from an Australian publication called “Beef Central,” the country’s largest agricultural association, the National Farmer’s Federation, just voted to put its weight behind an industry-wide move to net-zero emissions by 2050.

This is not to say that the farmers in Australia will give up raising cattle or sheep. What it means is that they are pushing to offset any emissions that come from raising cattle and sheep, along with other agricultural practices that emit GHGs, with actions that draw down carbon.

Solectrac electric tractor. Image: Solectrac.

Part of the solution, perhaps more important, is to reduce directly the amount of methane the livestock produce when digesting feed. Green Energy Times ran an article on this in June of 2017, “Research on Bovine Flatulence” (https://bit.ly/2YoQmfn). It turns out that much of the gas can be reduced by adding very small amounts of a common seaweed to the diet. But that is just a beginning of the reductions we can see by changing agricultural techniques.

We have a number of approaches to farming that reduce the amount of tilling down to practically nothing – or actually nothing at all. For example, mycologist Paul Stamets, author of Mycelium Running, has shown that in healthy soil, the crops have a complex relationship with soil fungi that is destroyed by tilling. With no-till farming, that relationship can be restored. And, interestingly, so can natural soil fertility, which means that we can avoid the nitrogen-based fertilizers the European Commission showed as a problem.

There are many other ways to reduce farming emissions with different no-till techniques. Wikipedia has an interesting beginning article on the subject, “No-till farming” (https://bit.ly/31h8rhh). It says that one of several reasons to use the technique is that it is often more profitable for the farmers.

Another new technology, which promises to convert deserts into productive farmland, was reported by CNN (https://cnn.it/2CO7JyA). It combines two ingredients, water and clay, in a slurry so fine it can be sprayed. When it is used to wet sand, clay binds with sand particles and the result is better water retention. A test in Dubai shows that it works.

Reducing pesticides can also reduce emissions. It also can eliminate some of the poisons that get into our food. And again, there are many ways to bring this about. One recently appearing example is the use of agricultural robots. CleanTechnica ran an article on these recently, “Swarm Of Tiny Robots Could Help Eliminate Pesticides” (https://bit.ly/3gi3mcV). Small robots that can talk with each other do certain farm chores that make many pesticides unnecessary. Typically, one robot goes through a field identifying needs, and it alerts other robots that are set up to perform specific actions. Weeds and insect pests are zapped one by one, as the robots patiently do their work. These robots can do many other jobs that could have been done by hand by human beings, if only human beings were as patient and as uninterested in pay scales as a robot.

Water seems always to be an issue for farmers. Over the past 40 years, Peter Andrews, an Australian farmer, has developed what is called “Natural Sequence Farming.” This technique uses nature, with a little human help, to improve soil and raise ground water levels by preventing rapid runoff. For example, willows, which are very thirsty trees and have no use in the area, were encouraged to grow along a stream on Andrews’ farm. Farmers nearby opposed the practice for a long time, believing they would lose access to the water the trees took up, but the practice was soon recognized as beneficial to all, because it raised ground water levels in the entire area by slowing the stream. Similar practices can be used elsewhere (https://bit.ly/3gd8yi8).

One issue that is of clear concern is the use of petroleum products on the farm. Whether gasoline, diesel oil, or some other product, these contribute to a farm’s carbon footprint. There are clear answers to this problem, and the agricultural robots are certainly one of them. Another is electric farm tractors.

John Deere has been working on farm tractors, but probably not what most people would picture when they think of that term. It announced development last year of driverless electric farm tractors, one of which gets its electric power from a cable instead of a battery. The control computer is quite capable of keeping track of the cable so it can be reeled out and in. The autonomous tractors detect where they are and where they should be going.

A number of smaller manufacturers are going into the business of electric farm tractors. Rigitrac, based in Switzerland, sells its products in Europe, and there are other companies in other parts of the world. Solectrac is a rather new company based in California, which sells more conventional looking farm tractors that are fully electric.

While electric cars, trucks, and buses have been in the news constantly, with new models coming often, farm tractors seem to appear rather slowly. The advantages to the farmer, including freedom from pollution and far lower operating costs, suggest that a great deal of progress might be coming soon.

This article barely scratches the surface of what we can use – and what we can discontinue use of – to reduce farming emissions to net zero. And the only differences the consumer should notice are better food and better health.

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