Soil erosion dynamics on a cultivated slope in the Western Polish Carpathians based on over 30 years of plot studies

Abstract

Soil erosion is one of the most important processes affecting land degradation, especially in mountainous areas. The main aim of this study was to assess the dynamics of surface runoff and soil erosion in the Carpathians (Poland), based on data from over 30 years of plot studies, determine the threshold of extreme soil erosion on agricultural slopes, and estimate the cover-management factor (C-factor) of the flysch mountains. The field research was carried out in the Bystrzanka catchment on experimental plots with potato, cereals and grassland crop. The average annual soil erosion on the potato plots was 25.67 Mg ha−1 year−1, which was 95.4 and 99.7% higher than the soil erosion on the cereal and grassland plots. Principal component analysis was used to identify the factors determining soil erosion in the Carpathians, taking into account precipitation parameters, soil conditions, plant growth phases and agricultural practices. There were positive statistically significant relationships (p < 0.05) between soil erosion and precipitation sum and surface runoff. Precipitation thresholds for soil erosion of various magnitudes were determined, and the extreme soil erosion threshold was calculated (8.79 Mg ha−1 for a single soil erosion event and 59.37 Mg ha−1 for the annual total soil erosion). In addition, the Revised Universal Soil Loss Equation was used to show the role of the C-factor (calculated based on long-term plot studies, and proposed for Poland in the literature) in soil erosion studies. Different C-factors reflect changes in average soil erosion of up to 69%. Long-term plot studies are key to agricultural production and sustainable development in mountainous areas.