Biogas digestate is a by-product of the biogas process and contains high amounts of nitrogen, which makes it a valuable organic fertiliser. In a field trial near Freising, different crop rotations for biogas production were established in 2004/05 and fertilised with digestate only or were not fertilised (controls). A wide range of methods for soil analysis was used between 2013 and 2015 to identify the methods capable of showing a biogas digestate effect on soil quality. We learned that aggregate stability, C and N contents, and the number of earthworms showed significant differences between fertilised and unfertilised plots, while pH, water infiltration, bulk density and pore size distribution were not able to show biogas effects
