Badanie zmian nasiąkliwości szkieletu glebowego w wybranych poziomach genetycznych przy zastosowaniu laboratoryjnej metody ścierania na przykładzie piaskowca magurskiego

The paper presents the results of the study of changes in the normal volume of absorption capacity of soil skeletons formed from the Magura sandstone in the Beskid Makowski area, and sampled from different genetic horizons. In the field of hydrology, the key issue in assessing the water storage capacity of the soil cover storage reservoir is the water storage capacity of the skeleton part. In the case of mountain soils, the issue of determining water storage capacity seems to be of importance due to the significant share of skeleton fraction in the soil cover. Moreover, the absorption capacity of the skeleton is related to the fraction volume. Soil test pits were executed in the area of Myślenice Forest District (southern Poland), in the habitat of Carpathian beech species Dentario glandulosae−Fagetum, in a stand of fir and spruce Abieti Piceetum. The scope of field work included sampling of 6 test profiles. In each profile, samples were taken from three identified genetic horizons. Sieve analysis method was used to determine the total content of skeleton and fine earth, and percentage share of each fraction. For each skeleton fractions, normal absorption capacity and bulk density were found. An important, supplementary part of the study was the isolation of fine−grained and coarse sandstone in each sample. After such processing, the collected material was compared with the material remaining after the successive stages of soil skeleton abrasion (weathering) in an aqueous medium, according to methodological assumptions. A device was used to perform this stage of the study. Changes in water storage capacity were mainly considered taking into account the fraction size and the location depth in a soil profile (without specifying the thickness changes). Differences were found between the absorption capacity of skeleton occurring naturally in the soil, and water absorption capacity of skeleton devoid of the outer layer of detritus as a result of the abrasion method. Water storage capacity values were decreasing after each successive step of the experimental run, along with increasing fraction size and the depth of their position in the profile. Preliminary results showed that the changes of absorption capacity are more strongly correlated with size of the fraction than with position in a genetic horizon.