An overwhelming amount of dust — quantities so large that you could never get your clothes clean — and blowing topsoil were common sights during the drought that hit North America 80 years ago.

The widespread use of conventional tillage on prairie farms played its part in the development of this environment. Conventional tillage is when farmers pass over their fields with a cultivator, disc or plow several times a year to break the soil to help with seeding. 

The negative side effects of this process are: increased soil emissions of CO2, soil compaction that prevents water retention during droughts and it results in nutrient loss that contaminates waterways. Aware of these consequences, University of Manitoba scientist Elmer Stobbe set out to help farmers seed directly into crop residue in 1973 by introducing the zero tillage technique. 

Zero tillage agriculture removes cultivation from the farming cycle, but it presented challenges such as planting the seed in the ground and controlling weeds. Using science and experience, Dave Lumgar, a farmer from Thornhill, Manitoba, developed a seed drill that pushed through the topsoil without the need for tillage. 

Prairie universities were also instrumental in developing crop protection products to kill weeds without harming crops. 

In a world affected by climate change, zero till agriculture enables food production to be an agent of climate change mitigation. The carbon footprint of agriculture decreases under this system because fuel consumption and disturbance of soil carbon are reduced. 

Research from Swift Current has demonstrated that when zero till is combined with a crop rotation — that includes nitrogen-fixing crops — soil carbon content increases, effectively removing CO2 from the atmosphere. 

This carbon-based material, called humus, is a climate buffer that holds water during droughts and acts as a filter to minimize contamination of drinking water supplies. The science behind zero till helps reinforce the three pillars of sustainability in agriculture — profit, planet and people. It helps to bring economic affordability for farmers, sequester carbon from the environment and preserves water quality. 

But this system is not without trade offs. With the adoption of zero tillage across the Canadian Prairies, herbicides must be used in the place of tillage to control weeds. Science has taken the lead again to address this challenge.

New machine-learning techniques are being developed at the University of Manitoba to identify weeds with cameras so that herbicide is applied only to weeds.

Today, farmers and researchers are using science to increase the sustainability of prairie agriculture in the future. In Minton, Saskatchewan, farmers Derek and Tanis Axten are using cover crops so their fields can host plants for 200 growing days a year, doubling the time compared to the average farm. 

In doing so, nitrogen-fixing legumes such as chickling vetch reduce the need for synthetic fertilizer and increase the soil’s ability to weather droughts — which are predicted to become more severe in Western Canada.

While droughts are still common in the Canadian Prairies, they aren’t marked by the dust storms our grandparents experienced during the Dirty Thirties. Science is leading to more innovative agricultural strategies that allow farms to support a sustainable environment, which benefits society and is more profitable for farmers.

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David Mactaggart