Summary:

The respiration rate activity in the soil were examined in the vegetative season in 2005 in the Kurówka River basin in three transects comprising twenty four sites. The transects were developed from the terrain elevation towards the Kurówka River and covered arable lands with rye and wheat, shrub and meadow communities, sedge rushes, and willow shrubs. On the study area sandy and clay soil with organic soil on the Kurówka River floodplain The plant communities were investigated using the commonly applied method of Braun-Blanquet including modifications by Matuszkiewicz (2001). In arbitrarily selected points, phytosociological 32 releves were executed. Nomenclature of species was taken from the Checklist of vascular plants of Poland (Mirek et al. 1995). The respiration rate activity in the soil was examined using the OxiTop® - Control system (WTW). The results were determined as the amount of oxygen consumption taken by aerobic organisms in the soil samples incubated during 12 hours in 20. Organic matter level were examined by Ostrowska et al. method (1991) Preliminary results of the respiration rate activity show that damp sites, characterised by a high respiration rate, comprised fresh and damp meadows (with dominant Glyceria maxima and Phragmites australis) in the summer and autumn period opposite to cereal crops. Higher content of organic mater in soil samples increase oxygen consumption by soil microorganisms. Studies on the activity of rhizosphere organisms will be continued in the next two vegetative seasons.