Environmental Sustainability of Canadian Agriculture: Agri-Environmental Indicator Report Series - Report No. 3

Soil Quality

When considering various aspects of soil quality together (Figure E-1), agriculture's environmental performance has a good to desired status, and generally improved over the 25-year period preceding 2006.

The overall improvement is mirrored by the individual performance indices for soil erosion, which moved into the desired status (Figure E-2), soil organic carbon change, which changed from average to good status, and soil salinization, which increased its status in the desired performance range. The performance index for contamination by trace elements was calculated only for 1981 and 2006 and was stable in the average status range. Improvements in land management practices, such as increased adoption of conservation and no-till practices, reduced use of summerfallow, particularly tillage summerfallow and increased forage and permanent cover crops were primarily responsible for the improved agri-environmental performance for soil quality.

The improved performance was driven by the western provinces where cultivated agriculture is extensive and is dominated by cereals and oilseeds. This agricultural region is most amenable to reduced-till and no-till practices. Increased soil cover resulting from these practices also improves soil moisture, in turn allowing a reduction in area of summerfallow.

Generally, higher rainfall in Ontario, Quebec and the Atlantic Provinces supports more intensive agriculture and a different mix of crops. Although soil quality agri-environmental performance in Eastern Canada improved over 25 years as it did in the rest of Canada, higher rainfall and a higher (though diminishing) reliance on conventional tillage systems both contributed to lower performance. Soil conservation practices such as reduced tillage, residue management practices and winter cover crops help maintain soil cover. These need to be continued in all agricultural areas of the country and expanded particularly in areas where crop type and tillage practices leave the soil exposed and vulnerable to erosive forces.

Water Quality

When considering various aspects of risks to water quality together (Figure E-3), agriculture's environmental performance currently has a good status. It does however represent an overall decline from a desired state in 1981. This overall declining performance is mirrored by the individual indicator performance indices, which generally moved from desired status in 1981 to good status in 2006 (Figure E-4). Increased application of nutrients (Nitrogen (N) and Phosphorus (P)) as fertilizer and manure was the main driver for the declining trend in the performance index for water quality throughout Canada.

The overall declining agri-environmental performance was observed in all regions of the country, however a significant difference between the prairies and the rest of Canada was found for the risk of water contamination by N. Eastern Canada and British Columbia have significantly higher residual nitrogen (more input from legume crops, fertilizer and manure than required by crops) and moister climates that result in more runoff and infiltration than in the drier Prairies. The generally lower rates of N application in the Prairies, combined with the drier climate and less infiltration and leaching, results in an overall N agri-environmental performance status of desired in the Prairies as opposed to a poor overall status in the rest of Canada.

In the case of phosphorus, the east versus west differences are not as significant. Performance has declined in the prairies from a desired status in 1981 to a good status in 2006, as significant increases in the ratio of crop land to farmland, continuous cropping and diversification in production, as well as significant increases in cattle and hog production resulted in increased P inputs from fertilizer and manure. In eastern Canada the status declined from 1981 to 1996 and then improved to a desired status in 2001 and 2006. The improved agri-environmental performance is related to implementation of nutrient management plans, regulations, conservation practices and beneficial management practices that decreased the P surplus particularly in Ontario and Quebec.

The shift of animal numbers from Eastern Canada to the Prairies has resulted in a declining agri-environmental performance for risk of contamination of water by coliforms, whereas in the rest of Canada, particularly Eastern Canada, overall declining animal numbers have resulted in a relatively stable agri-environmental performance for coliforms.

Increased efforts are required throughout Canada to minimize the risk of nutrient, pesticide and coliform movement to surface water bodies and leaching beyond the rooting depth of vegetation. This is particularly so in higher rainfall areas of the country. This risk can be further reduced through practices such as regular soil testing and adoption of precision agriculture (better matching agricultural inputs application to localized field conditions), that increase the efficiency of nutrient use. Practices that mitigate surface runoff, such as establishing riparian buffer strips, winter cover crops, maintenance of surface residue, etc. will also contribute to reduced risk to water quality.

Air Quality

When considering various agricultural atmospheric emissions together (Figure E-5), agriculture's environmental performance in air quality is good, having shown gradual improvement over the 25-year period to 2006. The gradual improvement is mirrored by the individual performance indices for greenhouse gas (GHG), which fluctuated but generally improved its good status over this time, as well as for particulate matter, which improved its status from 1981 to 2006. The ammonia emissions indicator could be calculated only for the last two reporting years but showed a slightly deteriorating performance from 2001 to 2006 (Figure E-6).

Improvements in land management practices such as increased adoption of conservation and no-till practices, reduced use of summerfallow, (particularly tillage summerfallow) and increased forage and permanent cover crops were primarily responsible for the improved agri-environmental performance for air quality. Adoption of these management practices, particularly in the Prairies, led to soils becoming a net sink for atmospheric carbon, which means more carbon is being sequestered in soil than is being emitted. The same practices have led to improvements in particulate matter (PM) emissions over the period of study. Increased numbers of livestock across the country between 2001 and 2006 is the primary reason for the small decrease in the ammonia emissions performance index.

Land management practices that favour sequestration of organic carbon in the soil, such as reduced tillage and residue management practices to maintain soil cover, need to be continued and expanded in order to maintain and increase the amount of carbon dioxide removed from the atmosphere and stored in the soil. Similar practices that reduce the number of field operations and protect the soil surface from wind erosion are effective in minimizing PM emissions. Improved animal feeding strategies and more efficient use of N in agriculture are examples of beneficial management practices that can be used to mitigate emissions of methane, ammonia and nitrous oxide.

Farm Land Management

How farm land is used and managed is a primary determinant of agriculture's effect on the environment. Trends in land use changes and beneficial management practice adoption provide highly relevant information to help understand the results from the environmental performance indicators.

Over the 25-year period from 1981 to 2006, agricultural land use increased in intensity across Canada as both the area of cropland and the proportion of cropland to total farm land increased, mainly due to decreases in pasture and idle land in eastern Canada and decreases in summerfallow in western Canada. In response to market opportunities, cropping patterns diversified with the proportion of oilseeds, pulses and forages increasing at the expense of more traditional cereal grains. Total numbers in all major livestock categories increased over the 25-year period for the country as a whole, but there was a significant shift in cattle numbers: eastern Canada declined 26% and western Canada increased 41%, in large part due to removal of government subsidies on the transportation of feed grain.

Concurrently, producers across Canada are implementing a number of beneficial management practices (BMPs) to manage manure, fertilizers and pesticides and protect land and water resources. Results indicate strong adoption of nutrient management practices such as soil nutrient testing, optimizing the timing, application and incorporation of solid and liquid manure and fertilizer, and increased manure storage capacity. Results also indicate that improvements could be made in other areas such as solid and liquid manure storage practices, livestock access to surface water and pesticide application. Soil conservation tillage and no-till practices generally increased across Canada, together affecting 72% of cropland in 2006, contributing to the overall improvement in soil health across Canada.

Canada's agricultural landscape is a mosaic of cultivated, natural and semi-natural land that is used by close to 600 species of birds, mammals, reptiles and amphibians. Agricultural landscapes are dynamic, with economic drivers sparking land cover change that can be either beneficial (summerfallow to pasture) or detrimental (wetland to cropland) to wildlife habitat. The loss of natural and semi-natural land cover and the intensification of agricultural operations resulted in a decline in average national habitat capacity on farmland from 1986 to 2006. The significance of this national trend can vary from one region to another depending on whether or not there is a high proportion of natural and semi-natural land covers in the broader landscape. Beneficial management practices such as conserving riparian areas, adopting conservation tillage, managing woodlands and implementing rotational grazing should be encouraged, particularly in agricultural regions that have limited wildlife habitat capacity and in areas where there has been a significant decline in habitat capacity.

Food and Beverage Industry

Eco-efficiency indicators for the food and beverage industry have been developed to assess resource use intensity on the basis of dollar of manufactured goods produced. The indicators have been developed for benchmark years, which means no national trend analysis is available at this time. Structural and product differences in the industry throughout Canada lead to differences in resource use intensity. For instance, the grain and oilseeds milling and the sugar and confectionery products manufacturing sectors are much higher energy users than seafood, meat and dairy products manufacturing. Also, types of energy used vary by region within a given sector and influence the energy use and GHG emissions intensity within the industry. Similar structural and product differences affect the performance for the use of packaging materials, water intake and discharge intensity. Future updates of these indicators will allow for trend analysis.