Closing the denitrification gap: applying the 15N gas flux method with an artificial atmosphere in conventional and regenerative agriculture
Year: 2026
Type: article
Abstract: Introduction Denitrification is an elusive process that remains notoriously difficult to measure under field conditions, yet it plays a crucial role as the only natural terrestrial sink for reactive nitrogen, especially in agricultural systems where large amounts of fertilizer are applied. Direct measurements of N 2 fluxes over extended periods remain rare in the literature due to technical challenges. Methods In this study, we quantified and characterized denitrification emissions under two contrasting land-use practices—conventional and regenerative (unfertilized) agriculture—using a recently developed custom method combining a 15 N isotopic tracer with an artificial atmosphere (improved 15 N Gas Flux method). We conducted nine field campaigns over one year to (i) assess method applicability, (ii) derive a first annual estimate of denitrification, (iii) understand controls on denitrification dynamics, and (iv) trace denitrification‐driven losses of applied synthetic nitrogen fertilizer in conventional agriculture. Results Our method successfully detected denitrified N 2 fluxes in 90% of measurements and yielded annual budgets of 22.12 and 2.41 kg N ha ‐1 yr ‐1 in the conventional and regenerative fields, respectively. Soil moisture and nitrate availability (particularly under fertilized conditions) were the main controls on the denitrification product ratio (N 2 O/(N 2 O + N 2 )). We estimated that 11% of applied fertilizer nitrogen was lost via denitrification in the conventional field, with 7.3% of this loss emitted as N 2 O rather than N 2 . Discussion These results underscore the role of fertilization management in shaping denitrification dynamics and its potential to act as a sink for reactive nitrogen, while modulating N 2 O emissions.
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7128772696