Liquid manure mixing and ammonia emissions

Before spreading, a complete mixing of the tank is necessary in order to apply an homogenous product and provide an even rate of nutrients in the field. The requirement on mixer performances can be determined according to yield velocity for lifting up the settled particles. Therefore manufacturers should clearly indicate the flow rate of each agitator and the expected velocity for each particular tank equipment. Nevertheless, it appears that over sizing the agitator will not have direct influence on the amount of emitted ammonia. When mixing is only performed at the end of the storage, emissions are moderately increased, but the pH of the manure is largely increased and will influence emissions during the manure application in the fields.