EN
This paper presents the results of the quantification of water erosion rate in the rolling old-glacial area of the Narew River valley-sides using the Universal Soil Loss Equation (USLE). The soil loss estimated using USLE for 7 study sites ranged from about 1 to 5 Mg ha⁻¹ yr⁻¹. These differences are the result of varied slope steepness ranging from 1.8% to 7.5% and the average slope length ranging from 172 m to 480, as well as varied soil texture. The impact of various crop rotations on the erosion rate was also studied. The results revealed that crop rotations with corn and potatoes caused higher rates of erosion. On the most gentle slope, the annual soil erosion increased by 0.5 Mg ha⁻¹ yr⁻¹, while on the steepest slope the soil erosion rate increased by 2 Mg ha⁻¹ yr⁻¹.1