Erosion and Sediment Control in Agriculture

Tuesday, June 21, 2022 at 3:00PM Mountain Time
Wednesday, June 22, 2022 at 7:00AM Sydney Time

Agricultural practices to reduce erosion and sedimentation
Presenter: Dr Gary Hawkins

Agriculture is said to be one of the larger sources of non-point source pollution with sediment being the main issue.  However, there are practices used by farmers and producers that not only help reduce erosion and sediment movement but also build soil health to increase infiltration.  This presentation will describe some of the practices used by farmers to reduce erosion and sediment movement and see how these practices are being used in the field.  Besides reduced erosion and sediment movement, conservation practices increase infiltration and improve soil health.  Both of the latter contribute to reduced need for supplemental water additions and increase the productivity of the soil. 

Wednesday, June 22, 2022 at 3:00PM Mountain Time
Thursday, June 23, 2022 at 7:00AM Sydney Time

Challenges and Lessons Learned in Quantifying Soil Erosion in Cropland: Human and Natural Drivers, Disciplinary Fragmentation, and Technological Innovation
Presenter: Dr Robert Wells

Since 1933, the United States government has been in the business of addressing soil erosion through assessment and conservation programs. Assessment of soil erosion has seen broad technological advancements in theory and tools, while conservation programs have evolved to include soil health. Numerous predictive models have been devised to express soil loss and the impact of conservation practices on soil loss. These numerical representations have been empirical and physically-based with both lumped and individual erosion process tools. Data used to calibrate and/or validate the models have come from long-term field observations, mostly at the plot scale, and laboratory investigations of the governing processes: rain drop impact dislocation, sheet erosion, rill erosion and gully erosion. While the last two processes may be viewed as a continuum, rill and gully erosion have received continued attention around the world. Efforts to understand these erosion sources have been expanding to include remote sensing technology, both in the laboratory and the field. At the center of these investigations lie our basic understanding of the general problem and an inability to define the processes we are attempting to define. Most are very comfortable with incision and widening processes but no one definition of rill or gully exists between the disciplines. This fragmentation has created issues within the communities that investigate these processes. We need one idea that encompasses the physical processes to be described and one consistent nomenclature. As technology improves and our focus becomes clearer, the foci will turn to the human and natural drivers within the landscape. Innovation in image processing and landscape stitching are coming; however, these tools will need to “see” the difference between a farmer’s tractor tire impression and an evolving channel within the field and/or the difference in soil loss following successive storms where a farmer scrapes soil along incised field channels between storms. These challenges must be addressed and clearly defined to enhance our ability to predict future erosion patterns within the landscape, regardless of the degree of climate change.