Yeah! We all say . . . how can Canadians complain about warming temperatures? Records were set all throughout March across the country—record highs or near record highs were recorded in Charlottetown, Halifax, Toronto, and even in remote northern climes like Island Lake, Manitoba. Nova Scotians—who already boast the mildest average year-round temperatures—also enjoyed unusually warm and dry days through March and over the Easter weekend. Most of us will cheer . . . but what are the implications of these unusual weather patterns?
Well, the news tells us that Nova Scotian firefighters were out earlier than usual brooming grass fires, and some maple syrup producers are saying they had only one-half of a season. But for our soils, what does this kind of erratic weather pattern mean—does it matter—and what can we do about it, if it does? Well, the breezy, balmy, sunny days we’ve enjoyed in March and early April should have us thinking about soil moisture. As winds and warm weather sop up moisture from our soils, will enough be left for good crop germination this spring?
One smart solution—and we’re seeing it used more and more in Nova Scotia—is retaining corn stubble on your fields over winter. This practice traps snow, and you can bet the farmer who does it has more soil moisture in his fields than if he had plowed them up last fall. This same smart farmer also discs his soil, rather than employing the more disruptive practice of mold board plowing—again, preserving good soil structure and water-holding capacity and so helping to ensure good crop germination this spring . . .
So, have our past efforts at soil conservation better prepared us for unusual weather and climate changes? Can we do more to prepare ourselves for the future? The answer is yes, and a resounding yes.
Depending on your region, future climate projections suggest wetter or drier conditions, or even both, in one season. What is common to all regions is the predicted increase in the seasonal variability of climate and the frequency of extreme events. These extreme events will impact soil in different ways, our water resources, as well as crop production.
One of the clear concerns related to extreme precipitation events is the increased risk of soil erosion, particularly if they occur at vulnerable times during the year such as the spring or fall. Extreme precipitation events will also increase the potential for environmental impacts on water resources. Whether it is contamination of surface water by increased runoff or groundwater as a result of greater leaching, extremes in precipitation have the potential to impact water sources. Beyond the concern for extreme events, however, is the general concern of how decreased rainfall may impact crop production. Addressing these concerns, whether they relate to extreme events or annual rainfall is largely an issue of implementation of soil conservation measures.
Over the past several decades the Soil Conservation Council of Canada has been promoting a wide range of soil conservation practices. These practices have improved the quality and productivity of our soils while decreasing impacts on the environment. To withstand extreme precipitation events our soils must be robust and resilient. Increasing the organic matter content of soils, reducing soil disturbance, increased residue cover, reduced frequency of summer fallow, all contribute to a robust soil structure that will be resilient to variations in climate and extreme weather events.
Just one example of the benefits of soil conservation measures can be readily seen in increasing the organic matter content of our soils. This practice not only stores carbon in our soils, which reduces our GHG emissions, and so potentially mitigating climate change impacts, it also improves soil structure. Improved soil structure increases both the soil’s water holding capacity (the amount of plant available water in the soil) and its ability to effectively drain when excess water is present. Better soil structure, increased residue cover, and reduced soil disturbance are critical to in erosion control. Soil conservation will be critical to allow soils to withstand more extreme rainfall events and more open winters that are predicted for some parts of the country
Strategic soil conservation measures allow us to reduce our greenhouse gas emissions, potentially mitigating long-term climate change impacts. Well-chosen measures and practices also improve our ability to adapt to climate change. In the end, soil conservation is a smart investment in the future of your farm.