Soil Erosion - This Year More Than Most

Did you notice all the soil erosion this spring? It is concerning, and it makes one wonder if we are forgetting all the important lessons we have learned. It did not seem to matter whether it was no-till or tilled ground, erosion was definitely increased this spring.

Why Did It Happen?

The conditions in late winter and early spring set the stage for increased soil erosion potential. Even growers that had soil erosion measures in place experienced erosion they hadn't seen for years. There were several thaws where the top few centimetres of soil had thawed, followed by significant rainfall events that carried saturated soil away. Two significant rain events in mid-spring dropped 37 mm (Apr. 25) and 28 mm (Apr. 30) in the London area. Rivers were full of brown water. Rills and gullies were everywhere in newly worked fields and some that were planted. Rain events of these severities can be more than no-till and residue cover can protect, where there is significant overland water flow. Many soils were overly wet this spring, increasing the overland flow and making soils more prone to erosion. Wherever there was some slope, significant water collected, resulting in the movement of soil and formation of rills.

No-till Soybean Stubble Ground, Mid-April 2009

Lessons Learned

We have to continue to be diligent in managing our soil resource. Although we can say that these heavy down pours are infrequent, they do happen. It doesn't take many of them to lead to significant soil loss. Climate change researchers predict more severe rainfall events and possibly less snow cover, so, we may see this scenario more often. Soil loss not only reduces crop productivity, but also impacts the environment. Contamination of surface water sources can result when fertilized, planted and sprayed fields suffer massive rill and overland water flow. These events can quickly raise the ire of the public and cause problems.

Keeping the Soil in Place

Landowners, who have worked hard to put soil conservation measures in place, need to ensure the maintenance is kept up. Grass waterways should not have been reduced in width over time. Consider additional measures to address new problems. For example, even winter wheat fields planted no-till into soybean stubble were suffering erosion this year. A living cover crop has the ability to buffer against erosion because the active root system and ground cover holds soil and reduces the punishing aspect of downpours. However, excessive concentrated flows are more than this can handle, so some method of diverting the water may be necessary.

Erosion In No-till Planted Winter Wheat, Early May 2009

For landowners who have not implemented a full soil conservation program, there are also management options that can be implemented to reduce erosion potential. These options include grassed waterways, buffer strips, drop inlets, rock chutes, drainage, water and sediment control basins, crop rotation, reduced tillage and cover crops. Producers need to evaluate the topography of their fields. There are many fields that should have grassed waterways or water and sediment control basins, but are bare soil from fence row to fence row. Aggressive fall tillage that occurred last year likely contributed to the problem. Very few fields are planted to cover crops. Many soil conservation measures do not require much extra effort or expense. Grants are available through the Environmental Farm Plan and Conservation Authorities to help cover the costs.

Soil loss is a very visible cost that we don't assign enough value to. Our soil resource is critical to our long term productivity and wealth as a province and a nation. If we don't take care of it, increasing public interest in environmental issues could bring unwanted attention or restrictions. More effort has to be taken by producers to save this valuable resource for the prosperity of themselves and the public.