Changes in the Properties of Luvisols, Planosols and Fluvisols Under the Influence of Agroproduction Activity from the Region of Sofia District

The soils from the Dolna Banya valley of Sofia district are formed under forest meadow, bush and tree vegetation. It has influenced their texture, natural fertility and the reaction of the soil solution. As they are located in a semi-mountainous terrain, surface horizons are subject to erosion processes and podzolization. The aim of the research is to establish the changes in the profile of Rhodic Luvisols which occurred as a result of natural influences and the type of production activity on them. The research has found that for a long time there have been changes in the surface soil horizons of all studied differences of Rhodic Luvisols. The process of podzolization continues to develop and there is an increase in the content of silt in the horizons below the humus horizon. In the case of Fluvisols, an increase in the fraction of coarse and fine sand is reported. In the case of moderately eroded Planosols land use has an impact on the soil texture. In the deeper horizons, when planted with raspberries, the content of silt and physical clay increases compared to the same soil difference in the area with the application of threefield crop rotation, compacted with cereals using a shallow mouldboard ploughing .