Manure Management Practices Important for Establishing Baseline Methane Emissions in Abbotsford

Dairy manure storages in Abbotsford emit less methane than manure storages elsewhere in Canada, mostly because of the shorter storage time. In a previous post, we saw that storage temperature dramatically influences methane emission. This post looks at the storage methods and timing as they also affect the baseline methane emissions from manure. Liquid manure storage produces more methane than solid manure storage. A longer storage period increases the amount of methane emitted. Dairy farms in Abbotsford are unique in Canada for two reasons:

1. almost all dairy farms in Abbotsford utilize liquid manure systems
2. the average manure storage period is lower than the Canadian average because manure can be applied to grassland during the late fall and early spring.

We have to consider regulation and best management practices. According to the BC Ministry of Agriculture (2009), “an offset project must result in GHG reductions beyond existing or proposed regulatory  requirements / industry standards.”

An applicable regulation is the Agricultural Waste Control Regulation (2002), where it states:
“A storage facility must
(a) be of sufficient capacity to store all the agricultural waste produced or used on the farm for the period of time needed to  allow for
(i)  the application of agricultural waste as a fertilizer or soil conditioner, or
(ii)  the removal of agricultural waste,
(b) prevent the escape of any agricultural waste that causes pollution, and
(c) be maintained in a manner to prevent pollution.”

The BC Ministry of Agriculture published the Environmental Guidelines for Dairy Producers (BC Ministry of Agriculture 1993). This document was intended to “describe management options that are environmentally sound, and which comply with existing Federal and Provincial environmental laws.”  The recommended manure storage time in this document was a minimum of six months in order to “store the manure during the times of the year when manure cannot be applied to cropland due to the risk of causing pollution.”  This document allows for some manure application on grassland during all months of the year, and up to 40% of the annual allowable application between September and December.

The BC Ministry of Agriculture (2004a) states that “Manure is considered to be a fertilizer. The growth characteristics and nutrient requirements of crops should be carefully considered before fertilizing. Manure should be spread onto cropland when chemical fertilizer would normally be spread.” (BC Ministry of Agriculture 2004). They stated that manure may need to be stored from 5 to 7 months depending on the location in the province and the local weather conditions. BC Ministry of Agriculture 2004b) states that “manure spreading is not permitted in late fall and winter, to avoid sensitive fisheries stages and periods of high rainfall.”

The BC Ministry of Agriculture recommends four to six months manure storage (BC Ministry of Agriculture 2006). “For most BC farms, four months is recommended and six months may be most desirable. Up to one year may be required depending on the crop planted and the ability to fertilize with manure. Sufficient length of storage should be provided to avoid spreading manure on land when there is a danger of runoff.”

The Manure Spreading Advisories (BC Ministry of Agriculture 2012) also provide guidance to maintain industry standards. “Manure application on perennial grasses is usually appropriate until the end of October as long as crop growth and warmer weather patterns (greater than 5oC) continue; fields are trafficable; and precipitation does not create runoff….Plan manure applications to empty storage facilities before the rainy season.” (BC Ministry of Agriculture 2012 September manure advisory)

Manure is an excellent fertilizer source if managed properly. It is advised to apply manure throughout  the growing season to meet crop nutrient uptake patterns and to keep pits empty before the start of the rainy season. (BC Ministry of Agriculture 2012 August manure advisory). BC Ministry of Agriculture (2010) provides guidance to when manure should be applied, which is 100% of available manure for corn production during April before corn planting, and up to 25% of available manure application in September if a cover crop is planted after corn production. For grassland, up to 25% of the annual manure production can be applied in late February or early March, and up to 70% during the growing season up to September after grass cutting.

Because most dairy farms grow both corn and grass, the maximum potential manure storage requirement is 4 to 6 months. Manure storages should be emptied in March or April for corn production, and emptied throughout the summer for grass production, and to allow the storage facilities to be empty at the start of the rainy season in October.

From a methane emission perspective, this is important as we can expect accumulation of manure from an empty manure storage during October through February when the temperature is cold and minimal methane emission is expected. From April through September, the recommendation is to utilize the manure as the grass crops are harvested, which essentially suggests that the manure storage time is less than 1 month.

The dairy industry in BC is unique in Canada. A research report based on 2003 statistics suggested that: “Most farms with liquid manure storage had a storage capacity of more than 250 days. Furthermore, 9.9% of farms had liquid storage capacity with more than 400 days.” (Statistics Canada 2003). In a table showing manure storage by herd size, 31% percent of dairy farms in Canada stored manure as a liquid in 2003. In British Columbia, 65% of dairy farms used primarily liquid manure storage. 14% of farms in Canada had manure storage capacity less than 150 days (approx. 5 months). In 1997 in Abbotsford, the median storage time on dairy farms in Matsqui was 3.3 months compared with 3.6 months in Sumas (Environment Canada 1997). Essentially all of the dairy farms in Abbotsford store their manure as a liquid.

The average amount of manure storage on dairy farms in Abbotsford appears to be approximately 6 months. Rising and Palmer (1996) found that 30% of dairy farms in Abbotsford (Matsqui and Sumas) had less than 2 months capacity for manure storage, and 50% had less than 3 months manure storage. They suggested that “manure storage was the most critical factor in the environmentally sustainability of the dairy farms in the Lower Fraser Valley.” They evaluated several different environmental sustainability factors and concluded that dairy “farms were operated at at about 60% of the recommended environmentally sustainability level and the water quality in the surface waters was ranked in the worst 50% of the monitored surface waters in British Columbia.” There has been a significant increase in manure storage capacity on dairy farms since 1996, particularly with public funding provided through ARDCorp, and it appears that most farms have approximately 6 months of storage capacity.

Because the dairy industry and manure management practices are unique in southcoastal BC, it is recommended that we estimate a methane conversion factor that matches the regional conditions. This will be estimated in the next post.

References:

BC Ministry of Agriculture. 1993. Environmental Guidelines for Dairy Producers in British Columbia. Prepared in cooperation with the BC Federation of Agriculture and the Dairy Industry of BC.

BC Ministry of Agriculture. 2004a.  Manure Storage and Use. Strenthening Farming – Right to Farm Order No. 870.218-44. http://www.al.gov.bc.ca/resmgmt/fppa/refguide/activity/870218-44_Manure_Storage.pdf

BC Ministry of Agriculture. 2004b. Fertilizers and Soil Conditioners.   Strenthening Farming – Right to Farm Order No. 870.218-37. http://www.al.gov.bc.ca/resmgmt/fppa/refguide/activity/870218-37_Fertilizers.pdf

BC Ministry of Agriculture. 2006. Manure Storage Structures. Farm Structures Factsheet. Order no. 383.000-1. http://www.agf.gov.bc.ca/resmgmt/publist/300Series/383000-1.pdf
BC Ministry of Agriculture. 2009. BC’s Agricultural Sector and the Greenhouse Gas Reduction Targets Act.

BC Ministry of Agriculture. 2020. Nutrient Management Reference Guide. Canada-British Columbia Environmental Farm Plan Program. BC Agricultural Research and Development Corporation. http://www.agf.gov.bc.ca/resmgmt/EnviroFarmPlanning/EFP_Nutrient_Guide/Nutrient_Mgmt_Guide_2010_documents/NutrientMgmt_RefGuide.pdf

BC Ministry of Agriculture. 2012. Manure Spreading Advisory #4 2012: South Coast Region Sept 6, 2012. http://www.agf.gov.bc.ca/resmgmt/ManureAdvisory/index.htm

BC Ministry of Agriculture. 2012. Manure Spreading Advisory #3 2012: South Coast Region August 1, 2012. http://www.agf.gov.bc.ca/resmgmt/ManureAdvisory/index.htm

BC Ministry of Environment. 2002. Agricultural Waste Control Regulation. http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/10_131_92
Environment Canada. 1997. Sumas and North Matsqui Watersheds. 1997. Farm Practices Survey. Fraser River Action Plan. DOE FRAP 1997-48. http://research.rem.sfu.ca/frap/9748.pdf

Palmer, M., and N. Rising. 1996. The development of an environmental sustainability parameter for agriculture. Canadian Water Resources Journal. 21: 13-25

Statistics Canada. 2003. Manure Storage in Canada. Vol 1 No. 1.  Farm Environmental Management in Canada. http://publications.gc.ca/Collection/Statcan/21-021-M/21-021-MIE2003001.pdf