July UPDATE to Manure Spreading Advisory #2 of 2018: South Coast Region

Date: July 2, 2018

Refer to Manure Spreading Advisory #2 of 2018 (April 23, 2018) for the current Advisory.  The following Update does not change the Advisory.   

Considerations for spreading manure during warm weather:

When spreading manure during the summer, it is important to consider the impact of high temperatures on nitrogen (N) loss from manure.  Volatilization of ammonia during and shortly after application is greatly increased when temperatures are high.  Several other factors including manure composition, time to incorporation, wind, soil pH and moisture, and application method will impact ammonia loss as well.  

Losing ammonia from manure is a direct loss of its fertilizer value and should be considered when planning application timing and calculating manure’s contribution to crop N requirements.

Spreading manure when temperatures are above 25°C can result in a loss of 50% of the ammonia N within three hours of application.

To avoid losing the readily available ammonium N from manure

  • Apply during the cooler times of day and when wind speeds are low
  • Use spreading equipment which results in less ‘air time’, such as a drop hose or injection system

Farmwest.com provides an Ammonia Loss From Manure calculator which can help predict the potential N loss during manure application.  


Producers are responsible for decisions regarding manure spreading. Legislation gives no specific dates for manure spreading but it does not allow for manure to be spread in a manner that causes pollution.

For further information, please contact B.C. Ministry of Agriculture:

Jeff Nimmo, P.Ag.                         604-556-3109

David Poon, P.Ag.                         604-556-3098

For questions of a regulatory nature, please contact the B.C. Ministry of Environment:

To report a spill                          1-800-663-3456

To report pollution                    1-877-952-7277

This Update is produced by government, in partnership with industry, to provide guidance to farmers regarding the Agricultural Waste Control Regulationand the Environmental Management Act. If a discrepancy arises between this document and the legislation, the legislation takes precedence. Following this advisory does not relieve anyone from their obligations under the legislation. The Province of British Columbia does not guarantee the accuracy or completeness of the information referenced here from legislation, and in no event is the Province liable or responsible for damages of any kind arising out of its use.

Filed under: