Another important factor affecting gaseous emissions is the
residence time and contact surface area between the slurry and the
atmosphere at different stages along the slurry management
process. Guerrin (2001, 2004) and Guerrin and Paillat (2003) have
developed dynamic simulation models to evaluate the operational
feasibility of different slurry management scenarios. The models
calculate, taking into account the resources available for transport/
spreading and the climatic conditions, the replenishment level of
slurry storage tanks in relation to the production of slurry, the size
of the storage tanks as well as the calendar and technique of slurry
application to crop land or delivery to treatment stations. In future
studies it would be important to apply such models to use more
precise estimates of the slurry-atmosphere contact area to calculate NH3 emissions as well as the effect of variable climatic and operational
conditions.