Soil erosion in Norway. An overview of measurements from soil loss plots

. Since 1980 soil erosion by water on agricultural areas has been measured in plot experiments conducted at the Department of Soil and Water Sciences at the Agricultural University of Norway. Meltwater in spring is the most serious erosive agent but rainfall on nearly saturated soil and hare soil also has a considerable erosive effect. Erosion as a result of heavy rainfall in the growing season occurs occasionally. A high proportion of water-stable aggregates and a high content of clay and humus are characteristics of a soil with good resistance to emsion. Tillage has a strong influence on soil loss and it has been found that spring tillage reduces the annual soil loss by 90% compared with autumn ploughing.