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Identifying The Agricultural Imprint On The Global N2o Budget Using Stable Isotopes, T Perez, S E. Trumbore, S C. Tyler, P A. Matson, I Ortiz-Monasterio, T Rahn, D W T Griffith

Faculty of Science, Medicine and Health - Papers: part A

Agricultural soils are the most important anthropogenic source of nitrous oxide to the atmosphere. We observed large shifts with time in the emission rate (from 170 to 16 ng N cm⁻² h⁻¹) and in δ¹⁵N of N₂O emitted (from −46‰ to +5‰ relative to atmospheric N₂) from a urea-fertilized and irrigated agricultural field in Mexico. We calculated overall instantaneous enrichment factors for the sampling period, which suggest that the microbial N₂O production shifts from nitrification (week 1) to denitrification (week 2). Isotopic signatures of N₂O emissions were …