Tillage erosion and its interactions with wind and water erosion

点击翻译按钮获取中文摘要

Accelerated erosion of soil through human activities is the major form of land degradation in Canada and in many other parts of the world, threatening our ability to produce food, damaging property, and contaminating air and water resources. Soil erosion by wind and water has been studied for several decades and these processes are well understood. A recent and major advance in soil erosion science has been the recognition of tillage erosion, the movement of soil by tillage, resulting in soil loss and accumulation. Tillage erosion is a separate process from wind and water erosion. In cultivated landscapes, tillage erosion is often the dominant form of erosion, moving great quantities of soil and resulting in severe soil losses. The applicant has thoroughly investigated the process of tillage erosion, making major advances in: measurement techniques, understanding of mechanisms, assessment of impacts, methods of control and remediation, and modelling. The most challenging and, therefore, largely unexplored area of soil erosion research is the interactions between erosion processes. Strong interactions are expected between tillage erosion and wind and water erosion. On upper slopes, tillage erosion exposes subsoil which is normally more erodible to wind and water erosion, and on lower slopes tillage erosion delivers soil to areas where water erosion is most erosive, incising channels. These interactions were first identified by the applicant in 1995 and have been the subject of theoretical study since. At the request of the federal government, the applicant has developed an integrated soil erosion model that predicts the combined effects of wind, water and tillage erosion. However, this model is limited to a simple overlay of model outputs for the separate processes. A truly integrated soil erosion model must account for the interactions between erosion processes. The objectives of the proposed research are to demonstrate and quantify the interactions between tillage erosion and wind and water erosion, and, based on these experiments, to develop a more accurate integrated soil erosion model. To do so, a series of experiments will be conducted in the laboratory and in the field.