Effect of autumn fire on microbial biomass content and dehydrogenase activity in two grassland soils

摘要

The effect of grassland burning on the content of soil microbial biomass and soil dehydrogenase activity was determined in mesocosm scale experiments established on Experimental Fields of the Institute for Soil Reclamation and Grassland Farming at Falenty near Warsaw, Poland. Experimental circular mesocosms, Im in diameter, were located on two meadows: one on mineral soil (Janki) and the second one on peat soil (Puchaly). The grassland mesocosms were burnt at the end of November, 2007. The soil samples were taken directly after the meadows were burnt and on April, July and November, 2008 from two levels 0-5 cm and 5-10 cm of non-burned sites (control), ecotones and burned mesocosms. The soil microbial biomass was determined by the chloroform fumigation - extraction method. The dehydrogenase activity in soil was measured using the TTC method. It was established that experimental grassland burning affected soil microbial biomass and dehydrogenase activity. The decrease of microbial biomass and activity of dehydrogenase after grassland fire was observed mainly in the case of surface soil levels and in the first months of the experiment.