EN
The aim of our study was to analyze the impact of such soil physical parameters as water potential (pF), microdiffusion of oxygen (ODR), redox potential (Eh), and air porosity (Eg) on respiration activity (RA), defined as CO₂ evolution after a 10-day soil incubation at 20℃. Moisture content was determined for a range of pF values (0, 1.5, 2.2, 2.7, and 3.2) that corresponded to water availability for usability by microorganisms and plant roots. Selected soil samples were extracted from the following soils layers: surface (0-30 cm), subsurface (30-60 cm), and subsoil (60-100 cm), and were classified (FAO) as Orthic Podzol, Eutric Histosol, and Haplic Phaeozem. ODR, Eh, and Eg increased with higher soil water tension, but generally a high variability of a examined factors was observed. Respiration processes in the surface layers were the most intensive (71.5-91.2 mg CO₂ kg⁻¹d⁻¹), whereas those in the subsurface and the subsoil samples were reduced by 65-98% to the level 1.6-19.2 mg CO₂ kg⁻¹d⁻¹. Our results revealed significant (p<0.001) relationships between soil RA and pF, ODR, and Eh as Eg level. However, correlation coefficients (r) varied as they were indirectly dependent on soil type and depth.