Composting manure

Resources for making and using compost


What is Composting?

Composting is the controlled management of a naturally occurring biological process called aerobic decomposition. When properly managed, composting microorganisms break down and stabilize organic materials over time to produce a uniform soil amendment and source of essential nutrients - compost.

Composting is an additional manure nutrient management and soil improvement tool for producers to consider.

For growing crops, vegetables or landscape plantings, compost is an excellent source of numerous essential nutrients and improves soil growing conditions.

As with all nutrient sources, compost and the soil it is being applied to should be sampled and analysed for nutrients, salts and other agronomic information to determine the proper application and soil mixing rate.

Is it Compost?

As established by the Canadian Council of Ministers of the Environment (CCME), for organic materials to be considered fully composted, the following criteria are to be met:

  • Windrow temperature is to exceed 55°C for at least 15 days
  • Require at least five turning events during the 55°C + period
  • The final Curing Phase is to be at least 21 days
  • Compost is free of pathogens and meets trace element and foreign matter limits
  • Meets stability (“doneness”) requirements
  • Compost Benefits

  • Reduces manure mass and volume over ½ (lower hauling costs), concentrates nutrients
  • Eliminates unpleasant odours
  • Destroys weed seeds, parasites and pathogens
  • Source of stabilized slow-release nutrients
  • Stabilized nutrients reduces risk of loss to ground or surface water
  • Improves soil properties such as porosity/aeration, water infiltration and retention
    capacity, soil organic matter content
  • Compost has a uniform, soil-like quality   
  • Potential Disadvantages

  • N loss - Greenhouse gases and ammonia (NH3) gas are emitted during composting
  • Requires extra time, labour and resources
  • Additional equipment and space requirements
  • Subject to weather conditions - can result in large time delays
  • Resources for making, monitoring and using compost

  • FACTSHEET: BMPs for Composting Manure and Other Organic Materials
  • FACTSHEET: BMPs for Using Compost for Growing Vegetables
  • Composting calculator tool for determining starting material mixing ratios
  • Composting protocol (includes formulas for calculating moisture content, bulk density
    and the self-heating test to assess compost stability and sampling procedures)
  • Windrow information and monitoring recording sheets (moisture and temperature)
  • Additional Composting Guides/Resources

  • Guidelines for Compost Quality, Canadian Council of Ministers of the Environment
    (CCME). 2005.
  • Composting Animal Manures, NDSU Extension Service. 2010.
  • On-Farm Manure Management Through Composting, Nova Scotia Agricultural College
  • Composting Mortalities, Manitoba Agriculture
  • Provincial Regulations

  • Manitoba Livestock Manure and Mortalities Management Regulation, M.R. 42/98
  • Select Additional Information Resources

  • Soil and manure analyses (Winnipeg): Central Testing Laboratory Ltd. and Farmers Edge
  • Compost analyses (Ontario): A&L Canada Laboratories Inc.
  • Solvita compost maturity test kit (6 pk)