It was one of those March mornings in 2016 – a dull sky, north-west winds, no snow on the ground but things were still generally frozen. As I rounded a bend in the road on the way into town, I saw dark smoke blowing above a tree line. I automatically assumed a fire, but as I got closer, the colour of the wind changed to brown. It was not fire; it was dirt, and tons of it. As I reached the intersection, I looked west, to see car lights piercing through the wall of dirt blowing across the road off a 100-plus acre field with no tree, snow or crop protection.
In the early 1900s, it was common to see drifts of sand that would settle next to fences, barns, homes, or any other sheltered spot from prevailing winds. Anywhere along what is now County Road 9 within the Municipality of Port Hope (formally Hope Township) was heavily deforested for a promise of productive farms. But in a few years, with the loss of the life blood of the area – top soil – from wind and water erosion, farms in the north area of Hope Township began to falter.
By the 1950s, many of these same properties were being sold to the Ganaraska River Conservation Authority (today known as the Ganaraska Region Conservation Authority – GRCA) for the best type of crop for that area – trees. For the productive farms that remained, many turned to growing tobacco; however, irrigation management was now becoming a problem, and with the ultimate downturn in the tobacco industry, it too left the farm landscape. At this point, the Ganaraska River watershed and Hope Township was a mix of livestock (dairy, beef, pigs and chickens) forage crops and cash crops (grains and corn); and top soil on the most erosion vulnerable areas were protected.
Today, after heavy conversion of pasture and forage land to cash crop (primarily corn, soybeans and wheat), and Chinese vegetables (bok choy, radish and cabbage), field erosion from wind and water is beginning to reappear. However, there is still time to adapt field level management to stop field erosion before it becomes too late.
So what can be done? Lots, and it all starts with controlling the mechanism of erosion. Erosion is a natural process with two distinct actions: soil detachment and movement. All erosion control methods are based on preventing detachment or reducing the carrying power of wind, water or tillage. Consider a tiered approach to controlling erosion:
Tier 1: Healthy Soil – A healthy soil is resistant to erosion because good soil structure comprised of organic matter is resistant to all forms of erosion. Soil health is supported by a combination of conservation tillage, crop rotation, the use of cover crop, and addition of organic matter. An effective conservation tillage program leaves 30 – 70% of the soil surface covered with residue after planting and throughout the rotation cycle. In order to achieve a minimum 30% soil cover after planting requires a minimum of 50% residue cover going into the fall.
Tier 2: Tillage Management – Changing the way your fields are tilled is also a quick remedy for certain types of erosion; particularly erosion from frequent tillage, or tillage on sloping fields, and sheet erosion. In both of these cases, crop yields are low on shoulder slopes and knolls. Erosion that leads to small rills can also be controlled by the way the field is tilled.
Tier 3: Erosion Control Infrastructure – When erosion gets out of hand in the form of large rills, gullies and bank erosion, certain tools such as water and sediment control basins (WASCoB), earthen berms or grassed waterways can be installed to manage the water that is carving your fields. In many cases, these areas can be fixed while limiting the amount of field area that is removed from production.
Tier 4: Wind Erosion – Unlike water, wind can ravage a whole field and remove valuable topsoil in large amounts. Just by increasing crop residue and diversifying crop rotation, wind erosion can be kept at bay. Consider planting a windbreak to further reduce the length (or fetch) of the field.
Tier 5: Permanent Cover – In some cases, certain areas of your property may need to be retired from non-permanent crops to permanent cover, such as pasture, hay or trees. Generally, it is economically advantageous to retire these pieces of land rather than spend money to maintain or try to improve productivity.
This winter, while the winds are blowing and the snow and rain is trying to move your most valuable asset – top soil – consider all of the ways you can help to manage erosion. It may be easier than you think! Contact GRCA’s Stewardship Technician, Pam Lancaster, for more helpful erosion control tips – 905.885.8173 or firstname.lastname@example.org.