INFLUENCE OF COGNETTIA-SPHAGNETORUM (OLIGOCHAETA, ENCHYTRAEIDAE) ON NITROGEN MINERALIZATION IN HOMOGENIZED MOR HUMUS

The influence of the enchytraeid species Cognettia sphagnetorum on N mineralization in homogenized mor humus was examined in a laboratory study. The mor humus was incubated in containers (150 ml) for 8 months at various temperatures and with different moisture levels. Two series were used, one with C. sphagnetorum and one without. The presence of enchytraeids in the cultures increased the level of NH4+ and NO3- by about 18% compared with the cultures without enchytraeids. Almost 40% of this difference was explained by the decomposition of dead enchytraeids. Temperature and soil moisture were the most important factors controlling the mineralization rate. The optimum moisture for N mineralization was between pF 1.6 and 1.1. © 1990 Springer-Verlag.