Monthly ammonia emissions from fertilizers in 12 Canadian Ecoregions

Abstract

, T. W. 2010. Monthly ammonia emissions from fertilizers in 12 Canadian Ecoregions. Can. J. Soil Sci. 90: 113Á127. Emissions of ammonia (NH 3 ) from agriculture have been associated with transboundary atmospheric pollutant transport and potential human health problems. Specifically, NH 3 gas reacts in the atmosphere to form fine particles (PM 2.5 ) that are subject to long-range transport and are considered to be associated with elevated risk of all-cause, lung-cancer and cardiopulmonary mortality. Agriculture is a major source of atmospheric NH 3 , and, of this, NH 3 from fertilizers is perhaps the most easily managed. Recent shifts in nitrogen (N) fertilizer materials and improved placement of urea and related fertilizers have resulted in marked changes in emissions. This paper describes a model developed to predict month-by-month emissions of fertilizer NH 3 , supported by surveys of farmers and fertilizer industry personnel that update information on fertilizer use. Compared with previous estimates by Environment Canada, the fraction of fertilizer N emitted as NH 3 is estimated to be 50% lower in the vast prairie regions (a very large reduction in total NH 3 ), and about 30% lower in eastern Canada. The estimate for 2006 is 1.0 )10 8 kg NH 3 emitted directly from fertilizer application, 73% of this in the prairie region, and much of this in May. Overall, this indicates 6% of the applied fertilizer N is lost as NH 3 gas. Clearly, emission estimates are strongly dependent on up-to-date information about farm practices.Key words: Model, urea, volatilization Sheppard, S. C., Bittman, S. et Bruulsema, T. W. 2010. É missions mensuelles d'ammoniac par les engrais dans 13 e´core´gions du Canada. Can. J. Soil Sci. 90: 113Á127. On associe les e´missions d'ammoniac (NH 3 ) venant de l'agriculture au transport transfrontalier des polluants atmosphe´riques et aux risques que cela pose pour la sante´. Plus pre´cise´ment, le NH 3 re´agit dans l'atmosphe`re en produisant de fines particules (PM 2.5 ) qui sont ve´hicule´es sur de grandes distances et qu'on conside`re accroıˆtre le taux de mortalite´ge´ne´ral ainsi que les taux de mortalite´attribuables au cancer du poumon et aux maladies cardiovasculaires. L'agriculture est une source importante de NH 3 atmosphe´rique et l'ammoniac issu des engrais est sans doute celui que l'on peut ge´rer le plus facilement. Une modification re´cente des mate´riaux employe´s pour fabriquer les engrais azote´s (N) et de meilleures techniques d'application ont donne´lieu a`un changement marque´des e´missions. Cet article de´crit un mode`le e´labore´en vue de pre´voir les e´missions mensuelles de NH 3 re´sultant des engrais, d'apre`s les enqueˆtes re´alise´es par les agriculteurs et le personnel de l'industrie des amendements agricoles qui actualisent les donne´es sur l'usage des engrais. Comparativement aux estimations ante´rieures d'Environnement Canada, on estime que la part des engrais N perdue sous forme de NH 3 a diminue´de 50 % dans la vaste re´gion des Prairies (ce qui re´duit conside...

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

“…The weekly emission inventories were based on the structure and emission factors used in the Canada-wide monthly emission inventories for key animal sectors: poultry (broilers, turkeys and layers), pigs, dairy, beef, and from applied mineral fertilizers Bittman, 2011, 2012;Sheppard et al, , 2010aSheppard et al, , b, 2009b). The basic model for emissions from each animal sector is (Sheppard and Bittman, 2013):…”

“…Emission factors were based on those previously published in Canada; those for outdoor storages, unheated housing, and land application of manure and fertilizers were adjusted based on mean weekly temperatures (Fig. 2) using correction factors reported in the previous publications (Sheppard et al, 2009b(Sheppard et al, , 2010a. Emission fractions for land spreading of slurry were reduced by 7.1% for each day with over 9 mm of rain in each week of the study (maximum of 50% reduction), to account for the effect of frequent rainfall in the region on emissions (Fig.…”

“…Emission fractions are based on generic emission factors that are specific to farming practices and environmental conditions. Emissions from applied commercial fertilizers were estimated as the amount of each form of fertilizer N applied each week, for each major crop, multiplied by the fractions of applied N that would be emitted as ammonia, based on local practices as in Sheppard et al (2010a). Weekly emissions from all animal sectors and fertilizers were totaled for each grid cell.…”

“…It also provided the opportunity to develop and test a high-resolution (4 Â 4 km) agriculture ammonia emission inventory; previous ammonia inventories in Canada were on the scale of province, Soil Land Classification units, and 50 Â 50 km grid cells (e.g. Sheppard et al, 2010a;Ayres et al, 2010).…”

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

“…Emissions from the application of fertilizer to crops that may be used to feed livestock is considered in Sheppard et al (2010). Since NH 3 reacts rapidly in the atmosphere and may be deposited at distance from source, atmospheric models have been developed to assist in tracking the chemical fate and transport of NH 3 (e.g., Makar et al 2003).…”