1. Simulating nitrogen balance in Canadian agricultural soils from 1981 to 2016.
- Author
-
Yang JY, Drury CF, Jiang R, Yang XM, Worth DE, Bittman S, Grant BB, Smith WN, and Reid K
- Subjects
- Nitrates, Manure, Agriculture, Nitrogen analysis, Ontario, Crops, Agricultural, Nitrous Oxide analysis, Soil chemistry, Fertilizers
- Abstract
Agriculture produces food, fiber and biofuels for the world's growing population, however, agriculture can be a major contributor of nitrogen (N) losses including emissions of ammonia (NH
3 ), nitrous oxide (N2 O) and nitrate (NO3 - emission from fertilizers, manure from housing, storage and field, as well as direct/indirect N3 O emissions from fertilizers, manures, crop residues and soil organic matter. The NO2 O emissions from fertilizers, manures, crop residues and soil organic matter. The NO3 - leaching is estimated based on the residual soil N (RSN) at harvest and drainage derived with the DeNitrification-DeComposition (DNDC) model. From 1981 to 2016, the N input from fertilizer and N fixation increased at a greater rate than N removal in harvested crops in all provinces of Canada, resulting in an increase in the RSN and N losses. In 2016, the Prairie provinces had lower N losses (11.7 kg N ha-1 ) from N2 O, NH3 and NO3 - compared with 43.2 kg N ha-1 in central Canada, and 76.5 kg N ha-1 in Atlantic Canada. However, the Prairie provinces had 84.3% of the total Canadian farmland (74.3% of the total Canadian N input), while central Canada had 12.9% of Canadian farmland (21.7% of the total Canadian N input). In the Prairie provinces, the total N2 O loss from fertilizer N ranged 4.4-8.6 Gg N whereas NH3 loss ranged from 17.1 to 44.6 Gg N and these values were influenced by both emission intensity and total land area. Total N2 O losses from manure were highest in Alberta, Ontario and Quebec resulting in 4.8, 4.4, and 3.4 Gg N and NH3 losses from manure were also highest in these 3 provinces at 61.1, 45.2 and 40.4 Gg N, respectively. Nitrate leaching was impacted by drainage volumes, soil type and N inputs. In the non-growing season, NO3 - leaching losses (36-yr average) were 63.3 Gg in Ontario and 57.5 Gg N in Quebec compared with 20.8 Gg N for Ontario and 35.5 Gg N for Quebec in the growing season. In contrast, the Prairie provinces showed higher NO3 - leaching in the growing season (23.1-37.4 Gg N) than in the non-growing season (10.4-13.7 Gg N). In summary, total fertilizer N increased the most over the 36 years in the Prairies which resulted in increased RSN and N leaching losses that will require further intervention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2023
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