Before the use of the slurry e.g. in the field, proper process techniques must be applied.
For farmers, the loss of NH4+ via the NH3 emissions will reduce the fertiliser value and amount of the animal manure. Therefore the implementation of measures to reduce NH3 emissions may contribute to reduce the oversupply of N to crops. One of these measures is the 1) acidification of slurry which can decrease the amount of NH3 emissions from the animal house, the store and after having applied the slurry to the land. Others include 2) solidification/stabilisation techniques which can be implemented but properly modified and adapted on site-specific applications (taking always into consideration the end-use of the treated material and the chemical characteristics of the slurry); 3) slurry cooling – a process which has similar characteristics with the geothermal heat generation. It also lowers ammonia levels in the stable thus contributing to creating better environmental and health conditions (Joergensen, 2009; European Commission, 2018). The Best Available Techniques (BAT) Reference Document for the Intensive Rearing of Poultry and Pigs (EC, 2017) provides the comprehensive list of all best available techniques for the slurries processing.