Farm practices survey and modelling to estimate monthly NH₃ emissions from swine production in 12 Ecoregions of Canada

Abstract

, J. 2010. Farm practices survey and modelling to estimate monthly NH 3 emissions from swine production in 12 Ecoregions of Canada. Can. J. Anim. Sci. 90: 145Á158. The swine industry in Canada has undergone rapid growth in some areas, but has also been restricted by a variety of environmental issues. Ammonia (NH 3 ) emissions are seldom mentioned among these issues, but emissions do occur and atmospheric NH 3 causes a number of impacts including contributing to odour, deposition into sensitive ecosystems and formation of secondary particulate matter, which is a health concern in some regions of North America. This paper describes a new model to estimate NH 3 emissions from the swine sector, relying heavily on a recent survey of swine producers to determine the present N and manure management practices. The key hypothesis was that NH 3 emission rates vary across Ecoregions and over time in a way that affects the degree of impact. The survey showed many differences across Ecoregions, most importantly related to feed crude protein and landspreading practices. The model estimated that grower pigs (!20 kg to market size) excreted on average about 8.5 kg total ammoniacal N (TAN) per (occupied) pig-place per year, and based on the national average farm practices, 25% of this TAN was emitted from barns, 5.3% was emitted from manure storage, and 17% was emitted during landspreading for a total of 4.8 kg NH 3 pig-place(1 yr (1 . The total loss for grower pigs ranged from 40 to 53% of excreted TAN across the 12 Ecoregions. Nursing sows emitted over twice as much per pig. Regions varied in reliance on homegrown feeds, which affected crude protein feeding and TAN excretion rates. Western regions had relatively low emissions from land application of slurry because of more extensive use of injectors. Emissions from grower pigs in winter were about 0.2 kg NH 3 pig-place(1 month(1 , mostly from barns, to as high as 0.7 kg NH 3 pig-place (1 month (1 in May, mostly from landspreading. Total emission for all of Canada in 2006 was 73 )10 6 kg NH 3 or about 13% of agricultural emissions in Canada. The results indicate that emission reductions can be achieved with greater use of low-emission application methods and reduced crude protein in feed. The emissions model can be used in future to assess the impacts from changes in feeding regimes and barn designs, and changes in practices such as animal density and increased access to outdoor spaces.Key words: Swine, ammonia, nitrogen, manure, emissions Sheppard, S. C., Bittman, S., Swift, M.L. et Tait, J. 2010. É tude et mode´lisation des pratiques d'e´levage en vue d'estimer les e´missions mensuelles de NH 3 re´sultant de la production porcine dans 12 e´core´gions du Canada. Can. J. Anim. Sci. 90: 145Á158. L'e´levage porcin a connu une expansion rapide dans certaines re´gions du Canada, tout en subissant les contraintes associe´es a`divers proble`mes environnementaux. Les e´missions d'ammoniac (NH 3 ) font rarement partie de ces contraintes, meˆme si elles existent et meˆme si le NH 3 pre´...

Elemental Composition of Swine Manure from 1997 to 2017: Changes Relevant to Environmental Consequences

“…However, total N and NH 4 –N concentrations did not change with time (Table 3). There was a significant decrease in TAN, and a possible cause is an increase in NH 3 volatilization (Sheppard et al, 2010), but this needs to be confirmed. Another explanation may be that with phase feeding, there was more efficient utilization of dietary protein and hence less excretion of urea, leading to less ammoniacal N in manure.…”

“…Phase feeding is the stepwise progressive change of feed composition with the age of feeders to match physiological requirements for nutrients. For example, up to eight phases are used for feeders in Canada, and in these, the feed crude protein (CP) content decreased from ∼21% CP for weaner pigs to 14% for market hogs (Sheppard et al, 2010). There can be cost benefits to this, as high‐CP feeds tend to be more costly.…”

“…There can be cost benefits to this, as high‐CP feeds tend to be more costly. There is also an environmental benefit: a large fraction (57–76%) of the N in swine manure is emitted to the atmosphere as NH 3 , with potential impacts such as formation of haze, production of harmful respirable aerosols, and eutrophication of N‐poor natural ecosystems (Sheppard et al, 2010). Because NH 3 volatilization is extremely difficult to control once urea is excreted, refinement of the diet to avoid oversupply of CP is a key environmental management opportunity (Nahm, 2002).…”

Weekly agricultural emissions and ambient concentrations of ammonia: Validation of an emission inventory

“…Emissions were lowest in late fall and winter largely because there was little manure or fertilizer spreading and low ambient temperatures reduced emissions from outdoor manure storages and the unheated dairy cattle houses. In contrast, poultry and pig houses are heated so temperatures and emissions are similar year around (Sheppard et al, 2009b;2010b). The first emission peak in spring occurred mid-February when manure application on grass crops was first permitted (Fig.…”

Potential for mitigating atmospheric ammonia in Canada

“…While there is little use of man‐made covers for slurry stores in Canada, crust formation is commonplace especially for dairy slurry (Sheppard et al ., , ). While low winter temperatures in Canada help to reduce emissions, increasingly slurry is stored in lagoons which are shallower and have a larger surface area than tanks.…”