Ammonia (NH3) is one of the N substances emitted by livestock farming that leads to environmental problems. The two main sources of ammonia emission from dairy housing are the urine puddles on the walking floor and the slurry in the pit. ‘Snelstal’ is an emission model that uses the chemical and physical processes in both compartments separately to quantify the total ammonia emission from a barn. Input parameters used in the model characterize the urine puddle on the floor and the slurry in the pit. Surface area, depth, urea concentration, pH and temperature of a urine puddle are the most important model parameters influencing the ammonia emission. However, validated methods to measure model parameter puddle volume are not available yet. The first objective is to develop and validate a method based on fluorescence techniques that estimates the amount of urine present on the floor and characterize the drainage process in practice.
A second source of ammonia emission is the slurry pit. It is known that when undisturbed organic matter forms a natural crust on the slurry surface. The role of frequent addition of faeces and urine and the effect of mixing on this crust and the resulting ammonia emission is unknown and the combination of frequent disturbed top layers in dairy slurry stored in pit underneath concrete slatted walking floors has not been researched before. The second objective is therefor to know the effect of vertical inhomogeneity in dairy slurry stored in pits on the ammonia emission.