A Modified Commercial Dynamic Chamber System for Measuring Soil Reactive Nitrogen Fluxes

Abstract

Reactive nitrogen compounds (NO, NO2, HONO, and NH3; Nr) play an important role in atmospheric processes and pose environmental and health risks. Though studied individually, their interactions at the surface–atmosphere interface remain unexplored. To address this issue, a comprehensive Nr dynamic chamber setup was developed by modifying a commercially available system for GHGs. System modifications to minimize surface loss for Nr were implemented. Proof-of-concept measurements under controlled lab conditions demonstrated that NO, NO2, HONO, NH3, and N2O emissions can be quantified simultaneously. The p-values for the NO, NO2 and HONO within a specific soil volumetric water content range (20-24%) revealed heterogeneity, suggesting a need to reconsider the soil sampling and handling techniques used in laboratory studies. Emission trends from urea and synthetic magnesium/zinc ammonium carbonate fertilizers provide preliminary insights into Nr release from fertilized soils.