Agricultural Ammonia Indicator

The Agricultural Ammonia Indicator (official name: Ammonia Emissions from Agriculture Indicator) estimates the ammonia emissions associated with Canadian agricultural activities from 1981 to 2011. Ammonia is a basic, reactive and toxic gas composed of nitrogen and hydrogen that can have negative impacts on the environment and human health. It is released mainly through naturally occurring processes, such as the breakdown of excreted urea (cattle and pigs) or uric acid (poultry). Ammonia emissions also come from nitrogen fertilizers containing ammonium or urea.

Overall state and trend

Ammonia emissions have been increasing as a result of agricultural activities in Canada. Since 1981, emissions from fertilizer have more than doubled (from 63,000 kilotonnes of nitrogen in 1981, up to 130,000 kilotonnes of nitrogen in 2011). Conversely, livestock-related emissions have been decreasing, particularly since 2006. These trends reflect Canada’s national trend towards more land under annual crops, and less area given to livestock and associated forage production.

Use the interactive map below to zoom in and explore different regions. Note that some of the highest emissions per hectare (relating to both livestock and fertilizer emissions) occur in the Mixedwood Plains region of southern Ontario and Quebec. The high population density in these regions increases the potential for human health implications. Other areas of relatively high emissions include the Aspen Parkland, Moist Mixed Grassland and Lake Manitoba Plain regions of the Prairies. The Lower Fraser Valley region of British Columbia also has relatively high emissions.

In addition to exploring the 2011 values, click the play button to view changes over time. Since 1981, there has been an increase in ammonia emissions across the Prairies, peaking between 2001 and 2006, and then declining slightly since that time. This trend is especially evident in Alberta, and to a lesser extent in Saskatchewan. Eastern Canada and the Maritimes show a stable but declining trend in emissions over the same time period. The total national emissions went from 333,136 tonnes of ammonia in 1981, rising to 420,866 tonnes in 2006, and falling to 371,258 tonnes in 2011. These trends can also be seen in Figure 2 and explored in more detail in the specific trends section.

Figure 1: Total ammonia emissions from livestock production and fertilizer application in Canada, 2011

Legend: legend

Use the interactive map in Figure 2 to explore the change in ammonia emissions between 1981 and 2011. It is apparent that emissions are increasing in the Prairies and declining in Eastern Canada.

Figure 2: Change in total ammonia emissions per hectare, 1981 to 2011

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These emissions trends can also be seen in the graph below, which reports in actual emissions, measured in kilotonnes per year. The most dramatic reductions in recent years have occurred in Alberta and Saskatchewan. Manitoba shows only a slight reduction since 2006, and for all Prairie Provinces, 2011 levels are higher than 1981 levels. The graph shows reductions in absolute emissions for Ontario, Quebec, the Maritimes and British Columbia.

Figure 3: Total ammonia emissions from livestock and fertilizer use by province or region (Maritime Region includes NL, NS, NB and PE), in kilotonnes of nitrogen, 1981 to 2011
Description of this image follows.
Description - Figure 3
1981 1986 1991 1996 2001 2006 2011
British Columbia 17 16 16 18 18 17 15
Alberta 81 87 87 127 137 138 111
Saskatchewan 65 73 73 90 93 99 95
Manitoba 32 36 36 45 49 53 51
Ontario 96 91 91 89 89 89 78
Quebec 77 70 70 72 73 73 66
Maritime Region 11 12 12 12 11 11 8

Agricultural Ammonia Emissions performance index

The state and trend of the Agricultural Ammonia Indicator can also be seen in the performance index below.

Figure 4: Ammonia Index
Description of this image follows.
Description - Figure 4
Year Index Value
1981 73
1986 71
1991 70
1996 60
2001 59
2006 56
2011 61

In 2011, the state of ammonia emissions resulting from farming activities in Canada was "Good". The index illustrates a variable trend, representing a longer-term increase in emissions from 1980s levels, but an improvement since 1996 values. This is due to a steady increase in nitrogen fertilizer usage, which has been more recently (since 2006) off-set by the decrease in livestock-based emissions following the decline in Canada's cattle herd.

The index tends to aggregate and generalize trends and so should be viewed as a policy tool to give a general overview of state and trend over time.

How performance indices are calculated

Specific trends

This section highlights a few other trends of interest. In some cases, these are occurring in certain regions and in others they are affecting certain sectors, such as the beef or dairy industries. This is not an exhaustive list; additional findings can be found in the full publication: Environmental Sustainability of Canadian Agriculture, Agri-Environmental Indicator Report Series - Report #4

Trend 1 – Increased ammonia emissions from fertilizer in the Prairies

As ammonia emissions are produced by nitrogen fertilizer application and livestock production, both factors affect the ammonia indicator results. The map below (Figure 5) shows the trend in ammonia emissions from nitrogen-based fertilizers on the Prairies, by comparing 1981 findings (shown on the left) with 2011 findings (shown on the right). This region has seen significant increases in ammonia emissions from nitrogen fertilizer over the past 30 years.

Figure 5: Change in ammonia emissions from fertilizer application between 1981 and 2011.

Legend: legend

Reasons for this trend 1

The primary reason for the increase in ammonia emissions from fertilizer is simply the increase in fertilizer use. In 2011, emissions from fertilizers accounted for 35% of the total ammonia emissions, an increase from just 22% in 2006. This increase has been necessitated by the shift away from livestock production – cattle production in particular – towards annual cropping, which requires more inputs. The graph below (Figure 6) shows how the consumption of nitrogen fertilizer in both Western and Eastern Canada has affected this trend in ammonia emissions. In 1981, national consumption was about 0.94 million tonnes of nitrogen, which more than doubled to 2.0 million tonnes in 2011. Consumption in Western Canada has increased by more than 150%, whereas consumption in Eastern Canada has only increased by 22%.

Figure 6: Nitrogen fertilizer consumption (millions of tonnes), 1981 to 2011
Description of this image follows.
Description - Figure 6
Region 1981 1986 1991 1996 2001 2006 2011
Eastern Canada 0.29 0.32 0.29 0.29 0.30 0.29 0.35
Western Canada 0.65 0.90 0.87 1.29 1.30 1.25 1.66
Canada 0.94 1.22 1.16 1.58 1.60 1.54 2.01

Trend 2 – Lower emissions from beef cattle

The map below (Figure 7) shows ammonia emissions associated with beef cattle production. Livestock emissions decreased by 22% from 2006 to 2011, with the largest declines occurring in Alberta, Saskatchewan and Manitoba. In 2011, the beef sector accounted for 35% of ammonia emissions, which represents a notable decline from 46% in 2006.

Figure 7: Change in ammonia emissions from beef cattle production between 2006 and 2011.

Legend: legend

Reason for this trend 2

The improvements in beef cattle-related emissions is a direct result of the decline in Canada's beef cattle herd, following the 2003 bovine spongiform encephalopathy (BSE) crisis. This, and other factors, has resulted in a reduction in the beef herd of about 2 million head, equaling a 14% decline since 2006.

Both these trends can also be seen in the graph below (Figure 8), which shows a decline in livestock-related emissions and a concurrent increase in fertilizer-based emissions.

Figure 8: Ammonia emissions in kilotonnes of nitrogen
Description of this image follows.
Description - Figure 8
Livestock Fertilizer
1981 269,812 63,324
1986 252,921 82,427
1991 257,635 78,176
1996 289,309 106,430
2001 304,560 106,533
2006 307,859 113,052
2011 240,846 130,413

Why this indicator matters

Ammonia is water soluble and readily reacts with acid gases in the atmosphere, generating ammonium compounds in the form of fine particulate matter which can contribute to smog and be detrimental to human health. The agricultural sector in Canada contributes the majority (85%) of the total anthropogenic ammonia gas emissions and hence secondary ammonium-based particles, especially in areas near large urban centres where livestock production and extensive fertilizer use occurs. Smog events can reduce visibility and have a negative impact on tourism revenue. Ammonium that is bound to particles or aerosols is recognized as an air pollutant that can travel long distances, often crossing political boundaries. In the soil it can be transformed into other important reactive forms of nitrogen, such as the greenhouse gas nitrous oxide and the water contaminant nitrate.

The two most pertinent consequences of ammonia emissions in Canada relate to the exposure of people living in population centres downwind of agricultural land and the direct loss of nitrogen, an essential and expensive crop nutrient, from agricultural operations. Canada-wide, the loss of 371,000 tonnes of ammonia from farms in 2011 is equivalent to approximately 15% of all the nitrogen fertilizer shipped to farms that year, which translates into an economic cost of around $400 million.

Agriculture has the potential to mitigate ammonia emissions by implementing beneficial management practices.

Beneficial management practices

Practices to reduce ammonia emissions focus on reducing emissions from fertilizer and from livestock. Nutrient management planning can help to reduce fertilizer-related emissions as well as emissions from manure, by only applying what crops need to grow. Incorporating the fertilizer or manure into the soil through techniques such as side-banding or injection can lower the risk of ammonia escaping into the atmosphere.

As feed nitrogen is the source of all subsequent ammonia emissions from livestock, emissions can be reduced though feed management whereby the amount of protein in the diet is closely matched to animal requirements. Losses from housing can be reduced by adding chemicals to bedding (e.g. acidifying agents) and using barn designs that segregate feces from urine and that allow floating covers for in-barn slurry tanks as well as absorbent filters on barn vents. Winter feeding of cattle on pastureland rather than in wintering feedlots can also help reduce emissions from livestock operations. Canadian emissions from manure storage are lower than those reported by other countries because of the very cold storage conditions and the formation of crusts associated with ample bedding and dry winter weather.

How performance indices are calculated

The agri-environmental performance index shows environmental performance state and trends over time, based on weighting the percentage of agricultural land in each indicator class, such that the index ranges from 0 (all land in the most undesirable category) to 100 (all land in the most desirable category). The equation is simply "(% in poor class multiplied by .25) plus (% in moderate class multiplied by .5) plus (% in good class multiplied by .75) plus (% in desired class)." As the percentage of land in the "at risk" class is multiplied by zero, it is not included in the algorithm.

The table below shows the index classes. The index uses the same five-colour scheme as the indicator maps whereby dark green represents a desirable or healthy state and red represents least desirable or least healthy.

The table below shows the index classes. The index uses the same five-colour scheme as the indicator maps whereby dark green represents a desirable or healthy state and red represents least desirable or least healthy.

The index classes
Scale Colour scheme Class
80-100 Dark green Desired
60-79 Light green Good
40-59 Yellow Moderate
20-39 Orange Poor
0-19 Red At risk

The index tends to aggregate and generalize trends and so should be viewed as a policy tool to give a general overview of state and trend over time.

Related indicators

Additional resources and downloads