Grainswest - Fall 2022

Fall 2022 grainswest.com 27 EROSION PAST AND PRESENT Though not nearly as extreme, the images McKenzie posted were alarmingly reminiscent of those taken during the dust bowl of the 1930s. At that time, the combination of severe drought and high winds swept massive dust clouds across 100 million acres of the Great Plains of North America. The Dirty Thirties ended with tens of thousands homeless and poverty stricken. A lot has changed since that time. Most Prairie farmers have adopted no-till or minimum-till practices. The use of chemical weed control has allowed them to maintain ground cover yet control weeds. The practices have worked so well soil erosion largely faded as an agronomic concern, until recently. Ironically, it was National Soil Conservation Week when McKenzie really started to notice the rise in wind erosion on both irrigated and dryland farms. “It just seemed like the entire country was blowing,” said McKenzie, whose main focus at the provincial government was soil and crop research. “The past two growing seasons were very dry with limited crop production. Further, the past two winters were very dry, very windy with very low snow cover,” said Ross. “Fields with limited protective crop residue were increasingly affected by reoccurring winds. Fields that were tilled in the fall or early spring before seeding were subject to more severe wind erosion.” Soil erosion can be an expensive problem. Healthy soil is essential for healthy plant growth, but it also adds resilience in times of drought, flood and fire, and it plays an integral role in regulating Earth’s climate. To quantify the cost of topsoil lost to wind erosion is no easy task. The cost of wind erosion, said McKenzie, is often expressed in terms of reduced yield potential or the cost of inputs required to replace lost nutrients, both of which are difficult to estimate. Unfortunately, there is very little information available on the quality and value of topsoil that becomes airborne and lost. In 1987, Agriculture and Agri-Food Canada (AAFC) soil scientist Johan Dormaar determined the organic carbon content of eroded soil material. Using the results of Dormaar’s