Manure Spreading Advisory #3 - South Coastal Region - April 22, 2012

The following advisory is produced by government, in partnership with industry, to provide guidance to farmers regarding the Agricultural Waste Control Regulation and 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.

  • Manure application conditions have improved slightly since the last advisory and well-planned manure applications may be suitable on select fields based on weather conditions.
  • 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.
  • Please read the entire advisory for details and important information to assist producers with decision-making about manure application and storage.

Current Conditions, as an indication of manure application suitability

Weather: Warmer temperatures with periods of rain and sun are forecast for the next few days in Abbotsford. Check your local weather forecast for details.

Soil: Soil temperature is around 6.4oC at Huntington and 6.1oC at DeRoche.

Crops: The T-Sum for Abbotsford is 446. A T-Sum of 200 is one indication of optimal timing for the first fertilizer application on well-established grasses (see farmwest.com_Climate_T-Sum Calculator).

Avoiding Overflowing Manure Pits

Some producers may still be faced with potentially overflowing manure pits due to late spring rains. Producers should plan to have enough manure storage to include the average expected precipitation (for example, 219 mm for Abbotsford in April and May as provided by Environment Canada) plus account for unforeseen circumstances such as excessive precipitation.

Allowing any uncontrolled release of manure is likely a contravention of the Environmental Management Act. If overflowing manure pits cannot be avoided, producers are strongly advised to identify temporary alternatives to manure spreading. Producers should examine alternative storage options on neighboring farm operations with no stock or consider dewatering a portion of their storage pits (use a temporary liquid separator). The separated solids should then be managed as solid manure and placed in a bermed and covered (confined) facility. If alternative storage options for excess manure are not available, please contact the Ministry of Agriculture or the Ministry of Environment (contact info below) for further advice.

Principal environmental risks associated with manure application include:

  • Surface runoff of manure nutrients and pathogens to water courses,
  • Groundwater impacts from leaching,
  • Short-circuit flow of manure nutrients and pathogens to water courses though drain tiles,
  • Soil compaction from operating heavy equipment on wet fields.

Given the above risks, the “Manure Spreading Advisory Committee” (consisting of industry and government representatives) recommends reviewing the risks and suitability of manure spreading.

Helpful Hints and Precautionary Measures for All Manure Applications

The following measures should be considered prior to manure application:

  • Manure is an excellent fertilizer source if managed properly. Consider manure use throughout the season so that your pits are empty at the start of the rainy season. Remember the 4 R’s: Right rate, Right time, Right method, and Right product.
  • Do not apply manure to areas of the field that are saturated or frozen or subject to flooding or runoff.
  • Do not apply manure to tile-drained fields if there is a potential for manure to flow through the drain tiles.
  • Apply manure to actively growing crops or if field will be seeded within 2 weeks.
  • Apply manure only when soil is trafficable and there is no significant rain (i.e. greater than 10 mm of rain or its equivalent in snow) forecast in the next 5 days. Events such as farm traffic, tillage, and livestock usage on wet fields increases soil compaction which leads to increased runoff flow from the field. Soil compaction can also slow the warming of the soil, decrease crop yields, and cause root damage and premature aging.
  • Protect surface waters from runoff by maintaining adequate setbacks to watercourses. At this time of year, a minimum 5 metre (16 foot) setback is recommended. This distance should be increased depending on a variety of factors including weather, topography, soil conditions and rate of application.
  • Apply manure at rates matched to crop nutrient requirements and consider: Plants at the beginning and end of their growth cycle require fewer nutrients.
      • It is recommended that a single manure application not exceed 50 m3/ha (approximately 5300 gallons/acre) for slurry or 50 tonnes/ha (22 tons/ac) of solid manure. If a higher application rate is recommended (based on nitrogen requirement of the crop), apply the manure in multiple applications with possible incorporation of the first application. These rates are based on the soil’s ability to absorb the manure.
      • Leave at least three weeks between manure applications to reduce the risk of soil surface sealing. The time allows soil microbes to break up the manure.
  • In areas of high rainfall and/or high leaching risk, apply nutrients in smaller, multiple applications to reduce the potential for runoff and leaching.
  • Using only manure as a nutrient source could lead to phosphorus overloading in the soil. Soil and manure testing is recommended.
  • Avoid applications in diverting winds or on excessively windy days.

Field Specific Notes

Perennial Grassland and Well-Established Cover Crops: High yielding perennial grasses can take up to 100% of their total annual nitrogen requirement1 in April and May. Consider smaller, multiple applications throughout the growing season as shown with the 1, 3, and 5-cut grass growth curves on page 26 of the Nutrient Management Reference Guide at When applying manure, follow the precautionary measures listed above.

Prior to Planting: Application may be considered if seeding within the two weeks of application and if all other precautionary measures are adhered to. Manure should be injected or incorporated as soon as possible after application. See the Ammonia Loss from Manure interactive graphs at:

Berry and Vegetable Crops: Berry crops can take up to 100% of their total annual nitrogen requirement1 in April and May. Avoid heavy manure applications as this could injure new plants and increase the risk of polluting groundwater. Use of properly composted manure is preferred. Timing of application should also consider that manure be applied a minimum 90 days prior to crop harvest. If applying manure, include the precautionary measures listed above. Keep an eye open for the on-line version of the Berry Production Guide with an updated Nutrient Management Plan for raspberry crops coming soon to 1 Recommendations are for nitrogen only. A nutrient management plan is recommended (provided free of charge through the BC Environmental Farm Plan) and would provide better estimates of actual uptake for nitrogen, phosphorus, and potassium.

Additional Resources

Canada-BC Environmental Farm Plan Program Trained Planning Advisors are available to assist producers with completing an Environmental Farm Plan. For more information contact the ARDCorp office in Abbotsford. • toll free 1-866-522-3447 or 604-854-4483 • B.C

Good Agricultural Practices (GAP)
The BC Good Agricultural Practices (GAP) Guide can assist producers to implement food safety practices at the farm. It offers a whole-farm approach covering all aspects of crop and livestock production. Visit

Agricultural Waste Control Regulation
This is the actual legislation that applies to manure management in British Columbia.

For further information, contact the BC Ministry of Agriculture:
Lolita Aumuller, AAg 604-556-3098
Geoff Hughes-Games, PAg 604-556-3102

For questions of a regulatory nature, call the BC Ministry of Environment:
George Rushworth, PAg 604-582-5211
Trevor Hamelin, AScT 604 582-5275

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