Methodological Features of Determining Basal Respiration of Organogenic Peat Soil Samples

Using organogenic samples of peat soils from two taiga subzones, the methodological features of determining basal respiration (BR) were studied. It was found that BR values calculated at the initial stage of incubation (30 min) significantly exceeded those obtained using the “classical” method (24 h) and gradually decreased over time; this trend was observed across all sample types. A dependence of BR on the sample mass and the ratio between the sample volume and the flask volume was identified. The values were higher with a larger incubation flask volume and a smaller sample weight. The CO2 concentration did not influence the BR dynamics: both at near-zero and relatively high initial CO2 levels (4400 ppm), the results showed similar trends. When assessing soil biological activity using the BR method, it was critically important to maintain consistent incubation time intervals and consistent ratios of sample and gas phase volumes, due to the significant role of physical processes in the dynamics of CO2 accumulation in incubation flasks. The standard 24-h incubation method showed results that varied minimally depending on methodological factors and is likely the most preferable approach for this type of experiments.