Section 5: Environmental management
A variety of practices have been adopted by farmers to manage the impacts of agricultural activities on the environment. Restoration activities, such as converting marginal cropland to pasture, planting riparian buffers, and protecting and restoring wetland functions, help maintain or improve the capability of the land to produce valuable ecosystem goods and services.
Many agricultural activities can have environmental impacts on land, water, and air. These environmental impacts will differ based on the farm location, farm type, and the specific farming and land management practices used as well as the timing of these practices (i.e., season of fertilizer application). For example, nutrients and pesticides can run off agricultural fields into surface water bodies or leach into groundwater. Increased phosphorus loading from agriculture is one of several factors that have resulted in algal blooms in both Lake Erie and Lake Winnipeg. 1 , 2 , 3
Nutrients and pesticides
A number of nutrients are essential for plant growth, in particular nitrogen, phosphorus and potassium. Commercial fertilizers and livestock manure are often used to supplement the nutrients in the soil to the levels required by crops for maximum productivity and economic returns. Applying manure also adds needed organic matter to soil, helping to improve soil structure. 4
Care must be taken, however, to apply these nutrients correctly to minimize impacts on water. If applied in excess, nitrogen and phosphorus in fertilizer and manure can run off into surface water bodies or groundwater, causing excessive growth of aquatic plants, such as algae, and the subsequent depletion of dissolved oxygen as the plants breakdown after they die. This oxygen depletion can change the composition of the aquatic community and, in extreme cases cause the death of fish and other organisms. 5 The safety of the drinking water supply, including the potential impacts on human health of nitrogen in drinking water, is also of concern to Canadians. 6 Several provinces have strict legislation with regards to nutrient management and manure handling.
Pesticides are applied to agricultural crops to prevent losses from weeds, insects, fungi and parasites. While pesticides can help maintain crop yields and quality, they also have the potential to contaminate surface water and groundwater. This contamination can affect ecosystems, including impacts on individual species and biodiversity and can potentially result in human health impacts. 7
In 2011, 69% of Canadian crop farms applied commercial fertilizers (Table 5.1). There was little variability in fertilizer application across the country—it was most commonly reported in Ontario and Manitoba (75%) and least commonly reported in British Columbia (63%).
In 2011, 69% of Canadian crop farms reported applying herbicides, 15% reported applying insecticides and 23% reported applying fungicides (Table 5.1). Herbicide application was most commonly reported by crop farms in Saskatchewan (79%) and Manitoba (77%) while insecticide application was most common in the Atlantic provinces (34%) and British Columbia (28%). Fungicide application was most commonly reported by farmers in Manitoba (42%) and least commonly by farmers in Quebec (10%).
From 2001 to 2011 there was a 4% increase in fertilized land area in Canada (Table 5.2). In 2011, the largest fertilized areas were found in drainage regions in the Prairies: Assiniboine–Red (7,496,870 hectares), South Saskatchewan (5,195,829 hectares) and North Saskatchewan (4,499,229 hectares). As a percentage of cropland area, the North Saskatchewan (76%), Assiniboine–Red (75%) and South Saskatchewan (75%) drainage regions also had the highest percentages of fertilized land.
From 2001 to 2011 there was a 3% increase in the area of farmland treated with herbicides, a 42% increase in the area of farmland treated with insecticides and a 114% increase in the area of farmland treated with fungicides (Table 5.3). The greatest areas of farmland treated with herbicides and fungicides in 2011 were in the Assiniboine–Red , South Saskatchewan and North Saskatchewan drainage regions, which are also the three drainage regions with the greatest areas of both farmland and cropland. The greatest areas of farmland treated with insecticides were in the Assiniboine–Red , South Saskatchewan and Great Lakes drainage regions. Several factors can influence the use of pesticides. For example, in the United States, the use of conservation tillage practices as well as the adoption of crops genetically engineered to tolerate herbicides have both been found to increase herbicide use. 8 , 9
Looking at application areas as a percentage of cropland reveals different patterns for the application of insecticide and fungicide. Drainage regions with the highest percentage of cropland area treated with insecticide in 2011 were the Okanagan–Similkameen (28.3%), Saint John–St. Croix (19.0%) and Maritime Coastal (15.7%). Drainage regions with the highest percentage of cropland area treated with fungicide in 2011 were the Okanagan–Similkameen (28.0%), Assiniboine–Red (24.5%) and Saint John–St. Croix (20.8%).
In 2011, livestock on Canadian farms produced almost 152 million tonnes of manure (Table 5.4). Cattle accounted for 84% of this production, pigs 8% and poultry 3%. 10 Over 50% of total manure production occurred in the South Saskatchewan and Assiniboine–Red drainage regions located in the Prairies and the Great Lakes drainage region in southern Ontario. These three drainage regions had among the highest inventories of cattle, poultry and hogs in the country.
This manure contained almost 1 million tonnes of nitrogen, over 255,000 tonnes of phosphorus and over 542,000 tonnes of potassium. The Newfoundland–Labrador, St. Lawrence and Great Lakes drainage regions had the highest nutrient production from manure per farm area.
Water is essential for crop and livestock production. In Canada, most crops are rain-fed but some are dependent on irrigation; during periods of little rain, irrigation is used to augment soil moisture, ensuring higher and more predictable crop yields. In 2005, irrigation accounted for only 1.8% of the total quantity of water that contributed to crop growth. 11
In 2011, agriculture used 1.8 billion m3 of water, 85% for crop production and 15% for animal production. Overall, the sector was responsible for 5% of the 35.4 billion m3 of water withdrawn from Canada’s rivers, lakes and groundwater by household and economic activities in 2011. 12 However, unlike thermal power generation and other major water users that discharge most water withdrawals back into the environment; agriculture consumes 13 most of the water withdrawn for use. Agriculture consumed approximately 84% 14 or 1.5 billion m3 of the water withdrawn for crop and animal production in 2011.
According to the Agricultural Water Survey, almost 1.7 billion m3 of water were used for irrigation in 2012. Almost 40% of this water was applied in July and 24% was applied in August, 15 when water availability is at a low and the pressure on water resources is peaking from competing demands. 16 The South Saskatchewan, the majority of which is in Alberta, accounted for 77% of the total volume of water used for irrigation. Drainage regions in British Columbia—Pacific Coastal, Fraser–Lower Mainland, Okanagan–Similkameen and Columbia—were responsible for 14% (Table 5.5).
The irrigation intensities for irrigated field crops (2,998 cubic metres/hectare) and forage crops (2,894 cubic metres/hectare) were higher than those for fruit crops (2,093 cubic metres/hectare) and vegetable crops (1,328 cubic metres/hectare) (Table 5.5). Field crops and forage crops made up 99% of the land that received irrigation in the South Saskatchewan—the drainage region that received the most irrigation in terms of volume and area in 2012. 17
Criteria air contaminants
Criteria air contaminants (CACs) are a group of pollutants that can cause smog, acid rain and other environmental and health issues. Agriculture is an important source of two CACs—ammonia (NH3) and particulate matter (PM).
Agriculture is the main source of atmospheric emissions of NH3, which is produced from livestock and poultry manure management and fertilizer application. When agricultural emissions of NH3 occur near population centres they can interact with sulphates and nitrates from industry to form secondary fine particulate matter (PM2.5), which can have harmful effects on both human health and the environment. Secondary PM2.5 related to agricultural NH3 emissions has been reported in southern Ontario and the Lower Fraser Valley in British Columbia. 18 From 1985 to 2011, emissions of NH3 from agriculture increased 29% from 354,480 tonnes to 458,051 tonnes. In 2011, agriculture was responsible for 88% of total emissions of NH3. 19
Dust from soil and biological material, droplets and particles from agrochemicals and bacteria affecting both indoor and outdoor air quality are the main agricultural sources of particulate matter (PM). 20 PM decreases visibility, contributes to stratospheric ozone depletion, acid rain and smog, and influences climate by altering the amount of incoming solar energy and the amount of outgoing terrestrial energy radiating back into space. PM has been linked to a number of cardiac and respiratory diseases as well as various forms of heart disease. It also can have harmful effects on vegetation. 21 , 22
From 1985 to 2011, emissions of total particulate matter (TPM) from agriculture decreased 14% from 1,832,225 tonnes to 1,581,049 tonnes. In 2011, agriculture was responsible for 8% of total emissions of TPM, down from 14% in 1985. Agriculture was the fourth largest source of TPM in 2011, following dust from unpaved roads (49%), construction operations (19%) and dust from paved roads (19%). 23
Greenhouse gas emissions and removals
In 2012, agriculture generated 56 megatonnes of carbon dioxide equivalent greenhouse gas emissions (Mt CO2 eq GHG), 8% of Canada’s total (Table 5.6). GHG emissions from agriculture increased 19% (9 Mt CO2 eq) from 1990 to 2012. A further 14 Mt CO2 eq were attributed to on-farm energy use in 2012, up from 8 Mt CO2 eq in 1990, a 75% increase. 24
These increases were due to higher populations of beef cattle and pigs, as well as an increase in the use of synthetic nitrogen fertilizers. 25
The widespread adoption no-till practices and the steady decline in the area of summerfallow land have resulted in cropland turning from a net source of GHG emissions to a net sink. 26 , 27 In 1990 cropland was a source of 12 Mt CO2 eq GHG to the atmosphere while in 2012 net removals of GHGs by cropland was 5 Mt CO2 eq. 28
The intensity of GHG emissions compares GHG emissions to the value of agricultural output; crop and animal production emitted 2.38 tonnes of CO2 equivalent emissions per thousand current dollars of production in 2010. 29 Over time, intensity measures can indicate whether the industry is becoming more efficient.
Environmental farm plan (EFP) programs, which help farmers assess the environmental issues or concerns on farms, began in Ontario in 1993 and now operate in all provinces. 30 Although participation is voluntary, 35% of Canadian farms had a formal EFP in 2011. In Quebec (72%) and the Atlantic provinces (53%), the number of farms with an EFP was greater than the number without (Table 5.7). Some differences in participation may be due to differences in the provincial programs, as well as with differences in provincial legislation targeting nutrient and manure management. 31
An EFP also includes an action plan detailing the beneficial management practices (BMP) that should be put in place to improve environmental conditions. 32 BMPs are farming methods designed to minimize potential negative impacts on the environment. Farmers across Canada have implemented a number of BMPs to manage manure, fertilizers and pesticides and protect land and water resources. 33 In 2011, 43% of Canadian farms with an EFP had fully implemented their plan’s BMPs while 52% had partially implemented them (Table 5.7). Quebec had the highest proportion of farms with fully implemented BMPs (76%).
Productive farmland is an essential component of agricultural ecosystems. Cropland—land producing field crops, hay, fruit, vegetables, sod and nursery crops—accounted for 55% of total farm area in 2011, followed by natural pasture (23%) and tame or seeded pasture (9%). 34 From 1971 to 2011, the area of cropland increased 27%, mainly as a result of large decreases in summerfallow (81%). Tame or seeded pasture areas increased 34%, while all other lands, including natural pasture, woodland and wetlands, idle land, and other lands decreased 16% (Chart 5.1).
Tillage and summerfallow practices
Proper land management can reduce erosion and increase soil structure and fertility, serving to preserve and enhance farmland. Agricultural soils that are covered, either by vegetation, crop residue or snow, are less susceptible to degradation by wind and water erosion. Tillage and summerfallow practices are two factors that determine how long soil is covered during the year. Other factors include the type of crop and the climate.
Tillage involves plowing and cultivating the soil in preparation for planting or seeding. Three types of tillage are commonly used in Canada. Conventional tillage incorporates or buries most of the previous year’s crop residue into the soil. Conservation or minimum tillage retains most of the crop residue on the surface. No-till involves direct seeding into crop residue, avoiding any mechanical tillage of the soil. 35 Climate, soil and crop type all influence the type of tillage used. For example, cereal grains, oilseeds and beans can be easily grown using conservation or no-till practices while potatoes are generally grown using conventional tillage.
There are advantages to each of the three tillage practices. Conventional tillage loosens and aerates the soil, allowing for good air exchange and root growth. However, removing residues from the soil surface leaves soils more vulnerable to wind and water erosion and accelerates the decomposition of organic matter. Crop residues left on fields from conservation tillage and no-till conserve moisture, soil structure and organic matter. As well, conservation tillage and no-till involve fewer passes with machinery through fields, resulting in fuel and labour savings.
Over the past 20 years conventional tillage has become less conventional, while no-till gained in popularity to become the number one option on farms nationally (this was particularly evident in Saskatchewan and Alberta). 36 Land prepared for seeding using conventional tillage decreased from 69% in 1991 to 19% in 2011 (Table 5.8). Land prepared for seeding using conservation tillage remained relatively unchanged at 24% in 1991 and 25% in 2011. No-till practices increased from 7% in 1991 to 56% in 2011. No-till practices were most common in the Prairies ecozone (64%) which contained 66% of the total area prepared for seeding in Canada.
Land use practices such as increased use of no-till practices and decreased area of summerfallow land have resulted in improvements in carbon sequestration due to higher soil organic matter retention, 37 and have also contributed to reductions in PM emissions. 38
Nutrient and pest management
Canadian farmers are implementing a number of BMPs to manage nutrients. Practices such as regular soil testing and precision agriculture—managing crop production inputs on a site-specific basis—can increase the efficiency of nutrient use. Soil nutrient testing provides valuable information that producers can use to match crop nutrient requirements with nutrient levels in soil and nutrients applied in manure and commercial fertilizers. In 2011, soil nutrient testing was performed annually on 20% of crop farms while testing was done every two to three years on 36% of crop farms. Thirteen percent reported no soil nutrient testing (Table 5.9).
To reduce the use of pesticides, farmers are also using a number of alternative methods of pest control. In 2011, 55% of crop farms used crop rotation to disrupt pest cycles, with more than half of the crop farms in Ontario, Saskatchewan, Manitoba and Alberta using this method of pest control (Table 5.10).
Grazing livestock management
Keeping livestock in an open field during the late fall and winter period—a practice referred to as extended grazing—allows manure to be deposited directly rather than using a manure spreader. However, care must be taken to ensure the deposits are spread throughout the landscape, to ensure that overgrazing does not occur and also to ensure that environmentally sensitive areas are avoided. Regularly moving feed, shelter and bedding sites help to achieve this.
In 2011, 39% of livestock farms practised extended grazing (Table 5.11). This proportion was highest in the western provinces, particularly Saskatchewan (65%) and Alberta (62%), where cattle farming is common, and lowest in Quebec (6%), where dairy operations are more prevalent.
Controlling livestock access to surface water prevents stream bank degradation and protects water quality. In 2011, 56% of livestock farms had pastures or grazing paddocks adjacent to surface water (Table 5.12). This proportion was highest in Saskatchewan (74%) and lowest in Quebec (33%). In 2011, 15% of livestock farms allowed no access to surface water, 18% allowed limited access, and 35% allowed unlimited access during the grazing season (Table 5.13). The proportion of livestock farms allowing no access was highest in Quebec (66%) while the proportion allowing unlimited access for the entire grazing season was highest in Manitoba (43%) and Saskatchewan (41%).
Other land and water management practices
Farmers have adopted a number of other BMPs that can improve farmland productivity and reduce environmental impacts. According to the most recent Farm Environmental Management Survey, 24% of farms had permanent perennial forages on erodible land, 20% used slow release fertilizer products and 18% added straw to improve soil condition in 2011. Cover or companion crops were used on 15% of farms and 9% planted winter cover or green manure crops (Table 5.14).
Producers in many provinces are required by regulation to maintain setback distances from water bodies. Riparian buffer areas—located on the banks of a river, stream, lake or other water body—help capture soil, nutrients and pesticides from running off farms, as well as providing stability to shorelines. 39 In 2011, more than half (54%) of farms with waterways maintained a riparian buffer for all of these waterways while 23% of producers with seasonal wetlands and 41% with permanent wetlands maintained a riparian buffer area for all of them (Table 5.15). This practice was most common in the Atlantic provinces, Quebec and Ontario.
Irrigators use a variety of practices to conserve water. In 2012, some of the most common practices used by irrigators were watering at night or in the morning, using water or energy saving nozzles, incorporating compost or other organic material into the soil or leaving stubble on fields to help retain moisture, and reducing irrigation water pressures. 40
Farms in the South Saskatchewan drainage region were the most likely to use water or energy saving nozzles, to reduce irrigation water pressure and to conserve moisture by leaving crop stubble and incorporating organic matter into soils. Watering at night or in the morning was particularly common in the Great Lakes, the Okanagan–Similkameen and the Fraser–Lower Mainland.
Farmers also make investments to offset their environmental impacts. According to the Farm Financial Survey, farmers who reported capital investments in 2011, invested an average of $6,810 per farm on environmental protection improvements, an average of $47,480 on manure storage construction and an average of $17,701 on pesticide, chemical and fuel storage construction (Chart 5.2). The higher investment in manure storage in Quebec is related to regulatory requirements, the type of storage structure required for liquid manure, and the large number of dairy and hog operations in the province. 41 , 42 , 43