NEW ASPECT OF SOIL RESPIRATION ACTIVITY MEASURING

Summary. The purpose of this paper was to introduce a new m ethod for measuring soil organic matter mineralisation at the start of incubation ( start respiration ‐ SR) , as a supplement for other types of respiration, like reactive respiration (RR), basal respiration (BR ) and long term respiration (LTR ). The effect of temperature and time of lessive soil incubation on CO 2 evolution was determined. Soil samples were incubated for 7 days at 28 o C to determine SR, RR and BR, and for 35 days at 25 o C to determine LTR. Statistical analysis showed that the total amount of CO 2 released from soil as well as the rate of organic car bon (C org ) mineralisation were significantly dependent on the time of soil incubation in all types of measured respiration. The results obtained confirm our hypothesis that determination of start respiration is justified when respiration methods for investigation of C org mineralisation in soil are used. In this case diss olved fraction of C org in soil solution is taken into account. Other types of respiration ( RR, BR and LTR ) expressed in time of incubation give us information about soil organi c matter degradability and availability.