The impacts of land use on the risk of soil erosion on agricultural land in Canada

摘要

Using established erosion models and national databases, A Soil Erosion Risk Indicator (SoilERI) was developed under the National Agri-Environmental Health Analysis and Reporting Program (NAHARP) in Canada to assess the risk of soil erosion in agricultural land from the combined effects of tillage, water and wind erosion processes. The indicator was build upon the Soil Landscape of Canada (SLC) polygon and was then aggregated to the province and national scale. It reflects the characteristics of theclimate, soil and topography and responds to changes in land use over the 25-year period between 1981 and 2006. The results showed that the risk of soil erosion on Canadian cropland has steadily declined with time since the 1980s, largely due to the adoption of the conservation tillage, particularly no-till systems. However, there are still areas in every province with risks of unsustainable soil erosion. The risk of soil erosion was greatest under potato and sugar beet production and corn and soybean produced with conventional tillage. Serious erosion occurs on an important portion of cropland in southern Ontario and in Atlantic Canada. The information obtained in this study could help the decision makers to better target the hot spot of soil erosionin different scales and to design the best management practices for a given region.