Tatistical Assessment of Alluvial-Meadow Soils Located in Busmantsi Sand and Gravel Mining Field, Sofia, Bulgaria

The paper presents the results of an investigation on Alluvial-meadow soils (Mollic Fluvisols), located in Busmantsi sand and gravel mining field, Sofia, Bulgaria. Soil samples were taken from twenty-five soil profiles at a depth of 0-100 cm. The changes in physicochemical properties were investigated at different soil depths and the relationships between different soil characteristics were tested using regression analysis. There are statistically significant equations that describe the changes in soil characteristics with depth for all soil characteristics except pH. There are over 30 out of 45 possible regression relationships between the soil characteristics studied. No relationships have been found to exist between pH and the other soil characteristics. There are statistically significant linear regressions between bulk density and a number of soil characteristics (total porosity, sand and silt fractions, SOM, TKN, P2O5, K2O). There are regression relationships between the clay fraction and the other soil texture fractions and between the clay fraction and all chemical indicators. There are regression relationships between SOM and TKN, P2O5, K2O. There are regression equations that describe the relationships between TKN and P2O5, K2O, as well as between P2O5 and K2O.