By Magpie Group
There’s no question farming produces greenhouse gases. However, Canadian farmers – who are responsible for the vital task of providing food to the world – are also helping to reverse climate change by storing carbon on agricultural lands.1 In fact, agriculture is an important part of the strategy in Canada’s drive towards carbon neutrality and sustainability.
Read on to find out how.
An introduction to carbon farming
Before we delve into discussing carbon and climate change, we first need to talk about the carbon cycle.
Nature uses carbon to store energy. In the air, carbon exists mostly as carbon dioxide (CO2). During the photosynthesis process, field crop and grassland plants remove CO2 from the atmosphere, turn it into energy and then release oxygen (02) as a byproduct. During growth, plants store carbon (C) as energy in their roots, leaves and stems. As the plants grow and later die, this carbon is left behind in organic plant material in the soil, often referred to as soil organic matter. This is where the vast majority of soil-stored carbon comes from. The natural process that removes carbon from the air is called carbon sequestration, also referred to as carbon farming.
If managed well, agricultural processes capture and store carbon in soil organic matter. Not only does this reduce CO2 in the atmosphere, it also provides more nutrients for plants and thus for growing food. Carbon farming is now recognized an important factor in addressing climate change.
Just what is climate change anyway?
The atmosphere (the layer that surrounds the earth) is full of invisible gases, some of which are greenhouse gasses (GHGs). There are many types of GHGs, including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) which are released by nature. They insulate our planet and keep it warm enough to sustain life. You may have heard this called the greenhouse effect.
The problem is that human activities connected with the use of oil and gas, transportation, buildings, electricity, heavy industry, agriculture, waste production and others are producing excess GHGs, trapping more of the sun’s heat than the Earth needs to support life. This has resulted in climate change.
Consequences of climate change include increased global temperatures (global warming), intense droughts, water scarcity, severe fires, flooding, melting polar ice and extreme weather events.
What has this meant for agriculture?
Climate change is altering the kind of crops farmers can grow, the length of the growing season and growing conditions. They bear the brunt of climate change in many ways:
- Higher temperatures and less rainfall can increase the need to irrigate, which involves watering crops using sources such as lakes and rivers rather than relying on rainfall.
- More frequent days with temperatures over 30°C reduce yields for crops like canola and wheat that don’t grow as well in high heat.
- More pests and diseases will survive over milder winters and thrive during longer, warmer summers.
- Inconsistent growing seasons, such as later spring frosts and earlier fall frosts, make it difficult for farmers to finish seeding and harvesting on time, sometimes meaning crops are destroyed and can’t be used for human food.
How does producing food create GHGs?
Agriculture, including both crop and livestock production, is responsible for about 8% of all Canadian greenhouse gas emissions.2
GHGs released from growing crops include nitrous oxide and CO2. CO2 is produced by farm equipment and cultivating soil. Nitrous oxide emissions are primarily a result of fertilizer use, including manure. Methane from agricultural activities also contributes to GHGs, mainly as a natural by-product from feed digestion in the stomachs of cattle, as well as manure from farm animals.
Modern farming practices are making a difference!
Carbon farming is one way that agriculture has decreased global greenhouse gas emissions. Farmers improve carbon sequestration by either increasing the capture and storage of carbon or reducing the loss of stored carbon, or more often, both! Canadian agricultural soils, particularly in the prairie provinces, are now a significant carbon sink – they capture more carbon than is released by farming them.
In the year 2000, for the first time in Canada’s history, agricultural soils sequestered more carbon than was released as a result of farmers’ commitment to improve soil health and stop soil erosion.
Farmers use beneficial management practices to lessen the impact that farming has on the environment. Some practices that build the soil carbon sink are:
- Conservation tillage results in more plant material (straw, chaff and stalks from the previous year’s crop) being left on the soil to be converted into soil organic matter and stop soil from blowing away
- Adding animal manures, which contain high levels of carbon, to soil as fertilizer
- Growing legumes like peas, lentils, beans, chickpeas or alfalfa which help produce nitrogen, an important soil nutrient, to create healthier soil capable of sequestering more soil carbon, faster
- Converting land not suitable for growing crops to grasslands for livestock to graze on
In addition to increasing soil productivity and sinking carbon, these practices enhance the quality of water running from agricultural land and provide a better environment for wildlife.
And it’s not just about crops! Cattle recycle carbon from the atmosphere, too. Cattle manure contains plant nutrients (carbon, nitrogen, phosphorus, etc.) that, after they decompose, provide nutrients for plants to grow.
Similarly, pasturelands – which are unsuitable for growing crops but ideal for raising cattle – are covered in plant life that removes greenhouse gases from the air and sequesters them in soil.
In fact, land used for grazing beef cattle in Canada is currently storing about 1.5 billion tonnes of carbon!3
Carbon farming is just one-way farmers are making a difference in helping protect the soil, our natural resources and the planet. Not only does carbon sequestration reduce the amount of CO2 that is released into the atmosphere, it also contributes to soil health, improves water quality, and creates healthier and more diverse ecosystems.