After the separation of raw manure, the liquid fraction contains the largest content of N and K. The composition of the liquid fraction depends on various parameters: type of manure, age of manure, adjustment of separator, use of polymers, etc.
Liquid fraction is a valuable NK fertilizer. Due to the high N / P ratio, in comparison with raw manure, more liquid fraction can be spread on the land in accordance with the soil fertilizing limits.
The nitrogen present in liquid fraction consists of 50-60% mineral N which makes this fertilizer quickly absorbed by the plant. Because separation also homogenizes the liquid fraction it is an easy-to-spread fertilizer that does not cause blockages in the injector.
If there is a surplus of liquid fraction of manure in Flanders, it is treated in a biological nitrogen removal system (nitrification-denitrification) which converts the ammonium to N2.