Ammonia emissions from irrigated pastures on Solonetz in Victoria, Australia

Abstract

This paper reports ammonia (NH ) emissions from irrigated, fertilized pastures grazed intensively by dairy cattle in Victoria, Australia. Irrigation bays (65 × 365 m) were grazed in rotation by 315 dairy cattle and daily emissions were measured in summer and autumn. After grazing for a few days, the bays were fertilized with urea at 50 kg N ha and irrigated with 50 mm of water. Passive NH samplers were used to measure horizontal fluxes of NH from different sectors of the bays directly and the corresponding surface emissions were calculated from the sampler data using a backward Lagrangian stochastic (bLs) model of atmospheric dispersion. Ammonia emissions from the whole herd during the gr..