Everywhere in the news today experts are talking about climate change, what is contributing to it and how we can lower it. You’ve probably read some articles advocating that to reduce your carbon footprint you could turn the heat down when you are away, or that you bike to work instead of drive. Some even say by eating a “low-carbon” diet you can reduce your carbon emissions, but what is a “low-carbon” diet?

While all these options can help reduce your carbon footprint, there are many misconceptions about a “low-carbon” diet and what agriculture’s role in carbon emissions is. The EPA has said that the ag sector accounted for 11% of the total greenhouse gas emissions in 2020, but agriculture can provide ways to capture those GHGs by using some of the latest technology and innovative practices.

The gases responsible for climate change are primarily carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Methane and nitrous oxide are especially harmful as they can stay in the atmosphere far longer and be more problematic than carbon dioxide.

Ruminant animals like cows, sheep and buffalo are emitters of methane, while nitrous oxide can be emitted by excess fertilizer usage in agriculture. Farmers are actively finding ways to reduce these emissions – feeding special diets that reduce methane production in ruminants, building methane digesters which capture methane before it goes into the atmosphere and testing soil regularly to apply the correct amounts of nutrients and yield monitoring of crops. Not only are these ways to decrease emissions, they can also lead to renewable energy sources to generate electricity and heat buildings.

On dairy farms, methane digesters pull the methane off the cows’ manure and turn it into a gas, which can then be used to power things on the farm or sold back to the electric company for credits. Methane digesters work when methane, the byproduct of anaerobic digestion of organic matter, is collected within a sealed system. The burning of the methane converts it to energy in the form of heat or electricity. The digestate, or solid material remaining, can then be used as nutrient-rich fertilizer, organic rich compost or animal bedding.

Digesters can also be set up for the co-digestion of household food waste, unused cooking oil and restaurant waste, eliminating the buildup of green waste in landfills and producing more GHG emissions.

The USDA encourages farms to soil test their fields and utilize cover crops to reduce soil loss and promote carbon sequestration. Farmers can participate in the Conservation Reserve Program (CRP), where the USDA will pay the farmer to retire environmentally sensitive cropland from production for 10 – 15 years. Cropland enrolled will be planted with grass or trees to sequester carbon and provide wildlife habitat; in return, the farmer is paid rent on the land to cover their costs.

Other options for farmers who want to keep working their land is to use no-till farming methods, or planting cover crops before or after their main crop. No-till farming is when the farmer does not loosen the soil prior to planting. Traditionally, farmers would turn over the topsoil with a plow then break up any clumps using a disk then plant their crops. No-till farming is where the soil is left undisturbed prior to planting, limiting the soil erosion and decreasing the amount of fuel spent.

No-till farming has its pros and cons and is not a viable option for every farmer based on their situation and the type of crops they plant. The deciding factors tend to be the cost to the farmer and the potential benefits.

Cover cropping is another way to reduce soil erosion. It’s when a farmer plants a crop in autumn intended to cover the soil over the course of winter. The crop is sometimes not harvested and either killed off or plowed under prior to spring planting. Some popular crops are rye and wheat because they can grow rapidly before winter, increasing their soil-holding abilities and potential as a second cash crop to the farmer.

The diets farmers feed to their cattle can also play a major effect on the amount of methane they produce. Cattle are fed daily a diet of carefully balanced forages, grains and minerals which meet their nutritional needs. There are some ingredients that could be added that can help reduce the amount of methane biologically produced by cows. Ionophores are synthetic compounds that control the growth of microbes responsible for methane production. Natural enzymes from fungi or yeasts can also be used to break down methane produced by the bacteria in the cows’ stomach. Studies have shown that farmers could see over 60% reduction in methane emissions by changing the diet to include these methane reducing additives.

In conclusion, agriculture offers many proactive solutions to lower its effect on climate change and see a more sustainable future. Farmers are taking many steps to reduce fertilizer usage, utilize the methane from cows in methane digesters and minimize GHG emissions from being produced by feed additives. In all these ways, modern agriculture is more sustainable than ever and as an industry is actively working to reduce their carbon footprint.

If you have further questions, contact CCE Ontario Ag Economic Development Educator Jacob Maslyn at 585.394.3977 ext. 402 or jlm563@cornell.edu.

by Jacob Maslyn