Reducing On-Farm Emissions and Energy Use

Climate change and agriculture are closely connected. Agriculture makes up 10 percent of greenhouse gas emissions in Canada, excluding on-farm fossil fuel usage and fertilizer production processes. Canada has pledged to lower greenhouse gas (GHG) emissions across the economy by 40 percent and reduce agricultural emissions by 30 percent from 2020 levels by 2030. 

In order to meet these targets, changes across the agricultural industry are necessary. The exact carbon footprint of Canadian farms varies greatly within different sectors of the industry but taking this variety into account, methane and nitrous oxide make up the greatest contribution to greenhouse gas emissions at 38 and 36 percent respectively, with carbon dioxide claiming the remaining 26 percent in 2018. Reducing on-farm emissions is a great way for farmers to take action on climate change. Action now will allow farmers to invest in the well-being of future generations while also protecting their farms from the uncertainty of the present. What does this action look like in practical terms? In this post, we’ll look at the top sources of agricultural emissions and explore how farmers can reduce each source without negatively impacting farm profit margins.

Carbon Dioxide 

Carbon dioxide (CO₂) is the most well-known of the greenhouse gases. Agricultural CO₂ emissions come from a variety of sources, including agrochemicals and energy consumption. While manure and nitrogen fertilizer also produce CO₂, we discuss reduction of these sources elsewhere in the article.

Agrochemicals

Historically, agrochemicals like pesticides, herbicides, insecticides and fungicides have been important tools in pest, disease and weed management. Our current agricultural system was not designed to take into account the externalities caused by the widespread use of agrochemicals, which have been found to affect biodiversity, water quality, and human health in addition to contributing to CO₂ emissions. Agrochemicals are responsible for CO₂ during their creation and their transportation, in addition to affecting the soil’s ability to sequester carbon. Although it is a small contribution to greenhouse gas emissions compared to the other emissions sources (accounting for 2.1 percent of farm emissions), reducing a farm’s reliance on these chemicals will also improve a farm’s carbon sequestration rate in addition to cutting input costs.

Instead of using agrochemicals, organic farmers and researchers have other methods for mitigating or neutralizing the threat of pest, disease and weed cycles. Some of these tactics include:

• Planting cover crops, as well as other practices like intercropping and crop rotations 
• Applying mulch or organic manure 
• Reducing tillage or timed tillage to counteract weed seed rains
• Improving biodiversity to attract the biological controls that keep pests in check (also called biocontrols) 
• Controlled grazing
• Crop protection products approved for use in organic systems

The goal of these practices is to build and protect soil health, which makes plants healthier and more resistant to weeds and pests, with the added benefit of acting as a carbon sink that removes CO₂. These practices also keep the soil covered which protects it from erosion. 

Many organic farmers use a combination of these preventative techniques to reduce weed and pest issues. For more details about specific practices for weed prevention, you can check out our blog post on Ecological Innovations On Regenerative and Organic Farms.

Energy Consumption

CO₂ emissions can also be reduced by scaling back energy consumption in cases where the energy is drawn from fossil fuels and cannot be generated from renewable sources such as solar or wind. Conserving energy should be an integral part of a farm’s sustainability efforts and has the added benefit of cutting fuel and electricity costs. Here are just a few ways farmers can conserve energy in different areas of the farm:

• Tractors and Vehicles: Tractors and other farming equipment are some of the most energy-intensive components of the farm system. Keeping this equipment well-maintained will ensure it runs efficiently and doesn’t use excess fuel. Are you using properly inflated, radial tires with excessive wheel slippage? Are you reducing the engine RPM speed when using a smaller implement? Are engine fuel filters and injectors, as well as air cleaners being replaced and serviced when needed? These are all questions that can be asked to find opportunities for fuel efficiency.  

• Field Use: Cutting back the usage of tractors and other farming equipment will also cut down fuel expenses and improve the equipment’s lifespan. Practising low- or no-till can significantly cut down on the number of times a tractor needs to go over the field, thereby reducing both fuel and labour costs. This also reduces the amount of CO₂ released from soil disturbance caused by tillage and the solarization of carbon stored in healthy soil.

• Greenhouses: Since a traditional greenhouse (large or small) has much of its structure composed of transparent material like glass or plastic, it often consumes a tremendous amount of energy to maintain an ideal temperature (on average 75 percent of greenhouse energy goes to heating). Insulating greenhouses wherever possible is a great way to cut down costs. This can be done through reducing heating leaks, double insulating with a transparent material such as bubble wrap or installing thermal curtains. Installing windbreakers will also reduce heat loss from wind exposure.  

• Lighting: Another drain on energy is lighting in the various buildings around the farm. Replacing and updating light bulbs to be as energy efficient as possible, using sunlight whenever possible and installing timers will make sure lights are not left on for longer than they need to be. 

• Grain Dryers:  Grain dryers waste roughly 40 percent of the energy they use. To limit this waste, use field drying whenever possible, make sure grain dryers are used to maximum efficiency and avoid over-drying.  Farms can also reclaim the heat from the dryer is a great way to get the most use out of them.

Methane

Although its presence is less abundant in our atmosphere than carbon dioxide, methane is an extremely potent greenhouse gas that is 80 times more effective at storing heat in the atmosphere than CO₂. As a result of this higher potency, human activity-produced methane is responsible for 25 percent of climate change emissions. 

In Canada, 40 percent of methane agricultural emissions are produced by livestock. Ruminant animals like cows, buffaloes, sheep and goats can produce 250 to 500 L of methane per day, with cows being the largest methane contributor. While methane is a part of a natural cycle and livestock manure is filled with beneficial soil-improving nutrients, improper management can damage water quality in addition to contributing to greenhouse gas emissions.

Many factors can contribute to the amount of methane an animal will produce in its lifetime, including diet and methods of manure storage and treatment. Ways to improve an animal’s diet to reduce methane emissions include:

• Switching the animal over to an improved foliage diet. This diet has been found to reduce methane emissions and can be achieved through rotational grazing. 
• Mechanically grinding feed into fine powder for easier digestion 
• Adding edible components to the feed like canola oil, coconut oil or seaweed for improved digestion
• Adding ionophores to the feed inhibits methane production in the livestock by roughly 25 percent.

Recycling manure to use as soil amendments for a crop is an integral part of organic agriculture. While it may be tempting to apply as much manure as possible, especially when there is a lot available, it is essential to apply the right rate. Manure contains three macronutrients: nitrogen, potassium and phosphorus. While nitrogen needs to be resupplied to the soil regularly, potassium and phosphorus are consumed by crops at a slower rate and the build-up of these nutrients can be damaging to the soil. Therefore, it is recommended that manure should be applied to meet the phosphorus requirements of the crop instead of the nitrogen requirements.

This can be done by taking into consideration the exact nutrient composition of the manure (it varies based on the animal species), the pH level of the soil and the crop that is intended for the field. 

Whenever possible, manure amendments should be applied immediately since storage facilitates an increase in the growth of anaerobic bacteria, which are responsible for high levels of methane emissions.  However, manure should not be applied to frozen or extremely wet soil (like the kind you’ll find in the spring, late fall or winter) since that would result in a high amount of runoff pollution. Similarly, manure should not be applied in extremely hot or windy conditions. As such, it is sometimes less environmentally destructive to store manure while waiting for favourable application conditions. The best ways to lower emissions for untreated manure include the following:

• Manure lagoons should be kept covered, which will reduce 80 percent of methane emissions. The trapped gas under the cover can be burned in a generator and converted into electricity. The cover will also provide odour control. 
• Store the manure in a cool environment to prevent the build-up of microbial activity.

Composting the manure also serves as a viable solution to this storage issue. Composting manure has many benefits including a reduction in odour, methane emission levels and overall mass. Compost is also easier to transport and has a longer storage life than manure. Compost also reduces the likelihood of runoff compared to manure, has lower release of nutrients and is less likely to contain weed seeds. It is important to keep in mind that when manure is composted, nitrogen levels drop but potassium and phosphorus levels remain roughly the same. These calculations should be considered when applying compost to the fields. The typical amount of compost needed is anywhere between 5-20 pounds an acre.

Nitrous Oxide

Nitrous oxide is one of the most abundant elements in the atmosphere, making up close to 80 percent of the air we breathe. Human activities have increased the amount of nitrous oxide in the atmosphere by 40 percent, contributing to the climate crisis. Nitrous oxide serves as a potent greenhouse gas that is 300 times more effective at capturing heat than carbon dioxide and has also been found to be damaging to the ozone layer. Agriculture is Canada’s main source of nitrous oxide emissions, which are primarily produced through the application of synthetic nitrogen fertilizers.

Nitrous oxide emissions come from multiple sources including livestock manure and exposed earth—but the greatest source of nitrous oxide by far is the application of synthetic fertilizers. When over-applied, these fertilizers can lead to both water pollution and greenhouse gas emission. Emissions from nitrogen fertilizer production and use have doubled since 1990, and are estimated to double again by 2050 without sufficient action to curb the trend.

Over-application of nitrogen fertilizers is common: farmers rarely take other potential sources of nitrogen – such as legumes, compost or manure – into consideration when calculating the amount they need to apply, and will often add even more than that over-estimated number onto their fields as ‘insurance.’ This excess nitrogen is not absorbed into the soil and as a result, roughly 40-60 percent of nitrogen applied to fields ends up running off into surrounding waterways.

There is a clear opportunity to cut down nitrogen emissions through reduced application without compromising yields—one that comes with an added bonus of reducing input costs as well. Farmers can cut down on nitrogen fertilizer use in several ways:

• Apply nitrogen fertilizer only when the ground is dry and there is no expected rain for at least seven days since nitrogen moves easily in water. 
• Consider using nitrification inhibitors, which will prevent nitrogen from leaching into nearby water
• Consider alternative forms of nitrogen including cover cropping/ green manure, compost, organic fertilizer, crop residue, legumes, crop rotation, intercropping, etc. 
• Consider transitioning to organic or implementing organic practices: organic farming relies on management practices that do not involve synthetic fertilizer, such as low-to-no tillage, cover cropping, rotational grazing and more. The Rodale Institute’s Farming Systems Trial (FST) study has shown that conventional farming systems produce nearly 40 percent more GHG emissions per pound of crop produced compared to organic systems, mainly from direct inputs.

For more details about limiting nitrogen emissions levels, you can check out our blog post: Nitrogen Fertilizer and Climate Change.

Bonus Emission Source: Food Waste

Another significant source of agricultural greenhouse gas emissions is food waste. Our current global agricultural system produces enough food to feed 10 billion people, the peak global population expected over the next thirty years and a far greater number than our current global population of 7.9 billion. Despite these numbers, an estimated 811 million people (roughly 10 percent of the population) go hungry.

Ontario alone produces 3.6 million tonnes of food and organic waste annually. This wasted food ends up in landfills where it rots and emits methane, in addition to all of the other emissions generated during its production. 

Food waste can be curbed at every stage of the food production chain:

Fields: Losses here are the least avoidable since there’s little that can be done about an unexpected or a particularly violent storm killing off portions of the crop. Food waste at this level, however, is also the least expensive. Food that never makes it off the field has had far fewer resources put into it compared to food at other stages of the production chain. Additionally, when damaged crops are tilled back into the earth they return nutrients to the soil to be used by future plants, minimizing the extent of waste they actually produce. Pre-selling crops or planting in accordance with market demand can help reduce waste at this level. 

Post-harvest: Due to high cosmetic and quality standards, many products with imperfections in shape, colour or size cannot be sold to consumers or distributed to retailers. Selling cosmetically flawed produce at a reduced rate, processing it into a value-added product, or repurposing it as animal feed are ways to reduce food waste at this level.

Distribution: Timing is everything when it comes to fresh foods. Ensuring clear communication and shipping within the local food system can reduce the risk of food waste through spoilage at this stage.

Retail: Most food waste occurs at this stage since display shelves at grocery stores are not conducive to long shelf life. Retailers rely on fully stocked, plentiful displays to entice customers, meaning produce is stored in less-than-ideal conditions that shorten its life. Imperfect foods (especially those showing early signs of rot) are culled at this stage as well. Retailers can reduce food waste by increasing the precision of their sales predictions and stocking accordingly to reduce the volume of unsold produce.

Household: Perhaps the most costly, household food waste can be avoided through public education, including on how to store, prepare and recycle food properly, how to shop wisely and make the best use of the food one buys, and more clarity on how to interpret best before dates. Learn more about reducing food waste at each stage of production in this webinar featuring Wolfgang Pfenning of Pfenning’s Organic Farm.

Final Thoughts

As Canada moves toward a  net-zero economy, all of us will have to alter the way we live and do business. Farmers have a lot to gain from reducing their on-farm emissions, including the chance to cut costs and help solve a problem that threatens their livelihoods.

The Government of Canada has published a calculator to help farmers reduce their on-farm emissions. You can access the calculator here and get started today.

The National Farmers’ Union has also recently released a comprehensive report that takes stock of agricultural sources of greenhouse gas emissions. You can download the report here, or learn more about how farmers can play a role in meeting Canada’s emissions reductions targets in Farmers for Climate Solutions’ Budget 2021 recommendation on effective agricultural policy solutions.

Organic farming offers a wide array of low-emissions management practices that can help farmers to boost farm resilience, maintain high profitability and play a role in carbon sequestration. Learn more about some of these practices in our latest article: Building Strength Through Biodiversity: How Can Farmers Cash In?

You can also access financial and educational support to facilitate your transition to organic farming by checking out our Organic Climate Solutions Campaign.