Monitoring of water erosion on arable farms in England and Wales. 1990–94

The incidence of soil water erosion was monitored in 12 erosion-susceptible arable catchments (c. 80 fields) in England and Wales between 1990 and 1994. Factors associated with the initiation of erosion were recorded, and the extent of rills and gullies measured. Approximately 80% of the erosion events were on land cropped to winter cereals. In 30% of cases, the initiation of erosion was linked to valley floor features, which concentrated runoff. Poor crop cover, wheelings and tramlines were also assessed as contributory factors in 22%, 19% and 14% of cases, respectively. In c. 95% of cases rainfall events causing erosion were ≥ 10 mm day -1 and c. 80% were >15 mm day -1 . Erosion was also associated with maximum rainfall intensities of >4 mm h -1 for c. 90% of cases and >10 mm h -1 for c. 20%. Mean net soil erosion rates were approximately 4 t ha -1 per annum (median value 0.41 t ha -1 per annum) and associated mean P losses 3.4 kg ha -1 .