An alternative way to assess water erosion of cultivated land - field-based measurements: and analysis of some results

In the early 1980s, the Ministry of Agriculture in England and Wales took the decision to assess whether water erosion was a problem, deciding to answer the question through field-based assessment rather than by using plot experiments. Although giving valuable information on the rates, frequency and extent of erosion, as well as delivery of sediment out of catchments, the results do not allow rates to be related to individual parameters so that rates of erosion can be predicted. The results from the monitoring scheme explain why farmers think erosion is of little importance. In the vast majority of instances, erosion does not affect how the farmer manages the land nor does it lead to a large enough removal or burial of the crop to affect farm profitability. The rates of erosion in England and Wales are compared with those measured in the field in other countries. Although, within any particular environment, mean and maximum rates cover a wide range of values, mean values generally relate well to climate and soils, rates being higher where storms are more frequent, or where intense rains or rain coinciding with snowmelt fall on erodible soils. Maximum values reflect rainfall intensities and amounts falling in rare storms. A field-based approach such as that described here provides a rapid and realistic way to assess erosion and the results can be validly compared across a wide range of environments. (C) 2002 Elsevier Science Ltd. All rights reserved.