Agricultural Odour

Agricultural odour is a major nuisance issue in rural areas, arising from livestock operations (including barns, feedlots, manure storage, and land application of manure). Unlike a single industrial stack, these odours typically arise from large open or semi-enclosed areas spread across a farm, making them harder to control with conventional end-of-pipe technology.

Because these sources are diffuse and weather-dependent, odour complaints from neighbouring properties are common, and ambient monitoring combined with good agricultural practice is often the primary tool for managing community impact.

Major Sources of Agricultural Odour

• Livestock housing such as barns, sheds, and feedlots
• Manure and slurry storage, including lagoons and stockpiles
• Land application (spreading) of manure and slurry on fields
• Silage storage and feed handling areas
• Mortality management and on-farm composting of animal carcasses

Key Contributing Factors

• Ambient temperature, wind speed, and atmospheric stability, which govern how far odours travel downwind
• Manure storage duration and agitation, which affect the release of stored odorous gases
• Animal diet and manure composition
• Proximity of the operation to residential or sensitive receptors

Agricultural Odour Control Strategies

• Covered or enclosed manure storage to reduce open surface area
• Timing manure application to favourable weather and incorporating it into soil quickly
• Biofiltration or biocover systems on barns and storage structures
• Diet modification to reduce odorous compounds in manure
• Setback distances and buffer zones from residential areas
• Ambient monitoring and dispersion modelling to assess downwind impact

See Also

• Diffuse Source, for how spread-out farm sources such as manure storage and land application are classified
• Passive Sources, for how open manure piles and lagoons with weak, unforced airflow are treated as passive sources
• Micrometeorological Method, for how weather conditions are used to estimate downwind odour impact from farm operations
• For further technical background, see the USDA NRCS Small Scale Solutions for Farm Odor Control guide.