Farmers and ranchers are already taking many important steps to lower their greenhouse gas (GHG) footprint. Practices and technology are helping farmers and ranchers mitigate and adapt to the changing climates. National GHG emissions are reported annually by sector and province in the National Inventory Report on Greenhouse Gas Sources and Sinks in Canada (2019).
GHG sources and sinks
Livestock’s key roles in climate smart agricultural production in Alberta include:
- efficiently converting feed inedible to humans into nutrient-rich protein
- consuming lower grades of crops, reducing wastage
- providing nutrient-rich manure to recycle nutrients back to crops, while increasing carbon storage in soils
Figure 1: Agricultural GHG management
Manure handling, storage and application
In 2017, GHGs from manure were about 12% of all agricultural GHGs in Alberta, less than 1% of provincial totals. The main GHG from manure is methane (CH4) when organic material decomposes without oxygen. Nitrous oxide (N2O) emissions also occur in moist conditions during manure handling, storage, and field application. Manure also emits ammonia (NH4) and nitrogen oxides (NOx), which contribute to odour.
Amounts of GHGs from manure during handling, storage and application depend on:
- volume and composition of manure
- animal type
- condition of the digestive tract
- quality of the feed consumed
- manure handling and storage method (liquid versus solid storage)
- application method (injected, incorporated, etc.)
- climatic and environmental conditions (temperature, oxygen level, sources of nutrients and moisture)
Handling and storage
Consider implementing these beneficial management practices during the handling and storage of manure:
- Move fresh manure to a covered storage to reduce added moisture, which reduces the amount of N2O emitted.
- Store at lower temperatures to reduce the microbial activities that produce CH4, such as below ground manure storage.
- Avoid adding or incorporating straw to manure because straw acts as a food source for CH4 producing bacteria, resulting in higher methane emissions.
- Encourage even distribution of manure and urine by:
- feeding rations over a large area
- frequently moving the bedding pile/area
- feeding on level ground or gentle slopes
Various technologies can be used to lower CH4 emissions from liquid and solid manure during storage:
- Impermeable floating covers (e.g. plastic) can be placed over the surface of the tank or storage to increase resistance between the manure liquid surface and the air, capturing GHGs. Methane is then removed by flaring or burning. In addition to reducing methane by 80% (when covers are used in conjunction with negative pressure), covers also provide good odour control.
- Composting solid manure produces a stabilized product that can be stored or spread on agricultural land with minimal odour, pathogens and weed seeds. However, care must be taken to ensure that adequate moisture and oxygen is supplied during the composting process.
Consider using these beneficial management practices before or during manure application:
- Test both the soil and manure before application to fields to ensure a proper nutrient balance for plant needs, which also helps to reduce the loss of nutrients as GHGs.
- Apply manure to soil as soon as possible since longer-term storage can encourage anaerobic decomposition and result in increased CH4 emissions.
- Apply manure shortly before crop growth to allow for the maximum amount of available nitrogen to be used by the crop.
- Avoid applying manure when soils are extremely wet as this leads to anaerobic conditions, increasing CH4 emissions.
- Avoid applying manure when the weather is hot and windy, or before a storm, as these conditions can increase N2O emissions.
- Avoid applying manure in the late fall and winter to avoid nitrogen losses and high emissions of N2O during moist spring conditions.
Animal feeding and husbandry
Feed type and quality, additives, and husbandry practices affect CH4 emissions. To reduce emissions, consider these beneficial management practices on your farm or operation:
- Select livestock to genetically improve feed use efficiency.
- Feed high quality feeds and appropriately balanced rations.
- Feed livestock based on sex, age and stage of production matching diet to nutritional requirements.
- Increase the digestibility of feed by mechanical (i.e. chopping, grinding or pelleting feed), chemical or biological processing.
- Reduce age to harvest.
- Improve forage quality.
- Implement strategies to improve fertility rates (i.e. pregnancy test cows, evaluate bulls breeding soundness and adopt a strict culling program).
Most GHG emissions from beef production occur when cattle are grazing on pasture lands that are not well-suited for growing annual crops. These lands support a wide range of ecological services that improve climate adaptation. Close to 20% of Alberta’s agricultural GHGs are removed by soil carbon sinks. These important GHG removals are primarily due to areas of perennial crops grazed by cattle. Soil carbon increases also result from reducing soil disturbance by tillage, and decreasing areas of fallowed land. Increasing soil carbon brings important benefits of improved water infiltration and nutrient cycling, while improving the soil’s capacity to adapt to changing climates.
Practices that increase efficiency, reduce GHGs and enhance climate resiliency include:
- converting marginal crop land to perennials to increase GHG removals by soil carbon storage
- reducing or eliminating cultivation to lower soil carbon losses from tillage and CO2 from use of fossil fuels
- managing stocking rates to avoid overgrazing and high concentrations of manure
- including non-bloating legumes to reduce amounts of added nitrogen
- extending grazing seasons with swaths or bales to lower CO2 from fossil fuel use and save on feed costs.
Biodigesters process animal waste under anaerobic conditions (no oxygen) to produce CH4, a biogas which can then be used to generate heat and electricity as an alternative energy source. The digested manure can then be used as a fertilizer. High capital costs are associated with this process although carbon offsets may be an option to help with some cost recovery. For more information on biodigesters, see Renewable energy.
GHGs and livestock production.
In Alberta, beef production represents about half of agricultural GHGs, or less than 4% of all GHGs in the province. This is due to the number of beef cattle in the province. The most common GHGs emitted by the beef industry are enteric CH4 from the digestive process, and CH4 and N2O from manure. Improved grazing management, feed efficiencies and manure management will help reduce GHG’s emissions and improve productivity. For more information on these practices visit Cow/Calf Operations and Greenhouse Gases.
The efficiency and environmental footprint of beef production in Canada has improved significantly. Advancements in technology and management have enabled beef production to lower GHGs while using fewer resources, with 29% less breeding stock, 27% fewer slaughter cattle, and 24% less land.
Figure 2. Total GHG emissions from production of one kilogram of Canadian beef has been reduced by 15% from 1981 to 2011.
Source: Greenhouse gas emissions of Canadian Beef production in 1981 as compared with 2011 (PDF, 493 KB)
The Canadian Roundtable for Sustainable Beef (CRSB) released its first National Beef Sustainability Assessment in 2016 renewing it every 5-7 years. It is a strategic assessment that benchmarks the environmental, social and economic performance of the Canadian beef industry. It highlights the areas where industry is doing well, and identifies opportunities for improvement. Under the environmental pillar, one of the National Beef Sustainability Strategy Goals is to reduce the GHG footprint of Canadian beef per unit of beef produced. For more information, see CRSB Sustainability Assessment and Strategy.
Greenhouse gas emissions from dairy cattle represent about 3% of agricultural GHGs in Alberta, or 0.2 % of Alberta’s total GHG emissions in 2017. Main sources of GHGs in dairy operations are from livestock management, cropping practices and manure management. Types of GHGs from manure are CH4 from liquid storages in the absence of oxygen, and NOx emitted during storage and soil application. For more information on management practices that reduce or mitigate GHGs, see:
Nutritional Changes that Reduce Greenhouse Gases (PDF, 476 KB)
Cropping Practices to Mitigate Greenhouse Gases (PDF, 391 KB)
Sources of GHGs from pork operations are buildings, liquid manure storages, and land application of manure. These represented approximately 1% of Alberta’s agricultural GHGs and less than 0.1% of Alberta’s total GHGs in 2017. One method in reducing GHG emissions is to formulate diets to match nutritional requirements as much as possible. For more information on management practices that can reduce GHGs, see Hog Operations and Greenhouse Gases.
A Life Cycle Assessment of Canadian Pork Production (PDF, 1.9 MB) was completed in 2018. It shows that the Canadian pork carbon footprint is among the lowest in the world.
The GHGs from poultry operations are primarily from feed production, manure management and on-farm energy. They represent about 0.2% of agricultural emissions in Alberta in 2017. Work to characterize GHG emissions in life cycle assessments is ongoing for poultry and egg production in collaboration with agricultural industry partners. See the Environmental Footprint of Egg: Agri-Food Production in Alberta.
Practices for improvement
Table 1 gives examples of practices that influence each type of agricultural GHG, along with associated challenges and opportunities. In addition to gains in efficiency and climate resiliency associated with lowering GHGs, programs are available to help with improvements. For more information on possible programs go to the Canadian Agricultural Partnership - Alberta.
Table 1. Ways to lower carbon footprints while increasing efficiencies and climate resiliency in livestock production.
|Practice||Reduce Methane||Reduce Nitrous Oxide||Reduce Carbon Dioxide||Increase Carbon Storage||Challenges||Benefits|
|Reduce Emissions - Feeding and Husbandry|
|Reduce age to harvest||moderate||minimal||Market fluctuations||Feed and yardage savings, potential for carbon offsets*|
|Improve feed quality, e.g. increase forage quality, use high energy grains, edible oils (up to 6% dry matter)||minimal||minimal||Higher costs, more intensive management||Faster weight gain market weight|
|Improve livestock fertility and survival rate||minimal||More management||Higher production|
|Genetic selection of feed efficient animals 5||moderate||minimal||Limited supply of breeding stock, cost||Feed and yardage savings, potential carbon offsets*|
|Beef Cattle - Grazing management, e.g. rotational||minimal||minimal||Higher costs, more intensive labour||More efficient weight gain, improved soil quality|
|Beef Cattle - Extend grazing, e.g. swath or bale grazing||minimal||minimal||More management, supplemental feed may be needed||Feed, fuel and yardage savings, manure additions add nutrients and soil carbon|
|Remove Emissions - Increase Carbon Sequestration|
|Land use change from annual to perennial crops||minimal||minimal||moderate||Lower returns||Fuel and fertilizer savings, improved soil quality|
|Conservation cropping||moderate||minimal||moderate||Seeding equipment, residue management||Fuel savings, improved soil quality, potential carbon offsets*|
|Apply manure to previously unmanured soils||minimal||Transportation costs||Recycle nutrients, fertilizer savings, improved soil quality|
|Plant windbreaks, woody crops||minimal||considerable||Monitor to manage weeds||Save inputs on marginal lands, stabilize riparian areas|
|Replace Emissions - Renewable Energy|
|Biogas from manure||minimal||Capital cost recovery||Less manure to land apply, potential carbon offsets*|
* Carbon offsets may be available with verifiable records to document practice improvement. See Agricultural Carbon Offsets.