Incidence du stockage hivernal du lisier des bovins laitiers et de son agitation subséquente sur les émissions de gaz.

Liquid manure storages emit greenhouse gases (GHGs) and ammonia (NH₃), which can have negative effects in the atmosphere and ecosystems. Installing a floating cover on liquid manure storages is one approach for reducing emissions. In this study, a permeable synthetic cover (BiocapTM) was tested continuously for 165‐d (undisturbed storage + 3‐d agitation) in Nova Scotia, Canada. Covers were installed on three tanks of batch‐loaded dairy manure (1.3 m depth × 6.6 m² each), while three identical tanks remained uncovered (controls). Fluxes were measured using steady‐state chambers. Methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) were measured by absorption spectroscopy, and NH₃ was measured using acid traps. Results showed covered tanks consistently reduced NH₃ fluxes by approximately 90%, even though a surface crust formed on controls after about 50 days. Covers continued to reduce NH₃ flux during agitation. Covered tanks also emitted significantly less CO₂ and N₂O than the controls (p‐value <0.01). However, CH₄ fluxes were not reduced, and therefore overall GHG fluxes were not substantially reduced. Short‐term trends in CH₄, CO₂, and N₂O flux provided insight into cover function. Notably, bubble fluxes were a key component of CH₄ emissions in both treatments, suggesting the covers did not impede CH₄ transport.