There’s a right time for everything.

Every year, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) receives calls about winter spreading. Long, cold winters that come after a wet fall and/or late harvest tend to make winter spreading more common. However, spreading on frozen or snow covered ground, on saturated soil or before major rain events is not a good practice, even if storages are full.

Spreading at the wrong time increases the likelihood of nutrient loss and runoff. Nutrient runoff not only pollutes lakes and rivers, it can also decrease your profits. Lost nutrients have to be replaced from another source, and additional commercial fertilizers cost money. Instead, apply at the best possible time to increase your profits while minimizing harmful environmental impacts. Apply nutrients when soil conditions allow crops to use the nutrients – just before planting or when crops are actively growing is best.

There are specific rules for applying nutrients if your farm is required to have a Nutrient Management Plan under the Nutrient Management Act. These rules apply between December 1 to March 31, and at any other time when the ground is frozen or snow covered. Frozen means there is five centimetres (cm) of frozen moisture in the top 15 cm of soil, and snow covered means soil has a layer of snow on the surface with an average minimum depth of five cm. Depending on the type of nutrients, these rules could include larger setbacks from surface water, requirements to inject or incorporate the nutrients, and/or only applying on land with lower slopes.

Even if your farm doesn’t require a Nutrient Management Plan, there is other environmental legislation that applies to everyone. Legislation such as the provincial Environmental Protection Act, Ontario Water Resources Act and the federal Fisheries Act contain general rules against the release of nutrients that may harm the environment.

Applying nutrients at the right time is one of the 4Rs of nutrient stewardship: apply nutrients at the right time, from the right source, at the right rate and in the right place. There are a number of methods that can ensure the right timing of nutrient application:

  • Increase your storage capacity if your farm produces liquid manure.
  • If your farm produces solid manure, look at options to store manure in either permanent or temporary storages.
  • Talk to your neighbours about short- and long-term arrangements for additional storage capacity.
  • Look into other operations that may take manure, such as a facility with an anaerobic digester, a mushroom farm or a manure broker.
  • Look at the weather forecast and delay applying if the forecast calls for rain or snow in the 72 hours after you plan to apply.
  • Allow for enough time, equipment and resources to apply at the best time.
  • Make sure application timing is a priority in farm management decisions; don’t leave it until it’s too late.
  • Create a good contingency plan that includes options for poor weather and emergencies.

Visit our website to find our factsheet, “Winter Application of Manure and Other Agricultural Source Materials,” and other resources to help you with storages, contingency planning and knowing the right time to apply. You can also contact the Agricultural Information Contact Centre for more information at 1-877-424-1300 or