The influence of three different farming systems on the earthworm populations at Burgrain

Between 1997 – 1999, earthworm populations were investigated in a six years’ crop rotation with three different farming systems at Burgrain. The biomass was mainly influenced by the crop specific cultivation method. Especially negative for anectic groups of species were ploughing in autumn before winter wheat and ploughing in spring before maize (periods of main lumbricid activity). During the following two years of meadows, the earthworm populations recovered again. The number of earthworms increased by 34% and the biomass increased by 66%. Among the farming systems, only small differences were found. However a detailed analysis of the communities of earthworm showed that significantly more earthworms of endogenic species were present in organic farming systems than in the intensive farming systems.