A practical path forward is to right-size phosphorus, monitor crop response, and foster robust root systems. With stronger roots, active microbes, and better soil structure, farms can protect water, store more carbon, and remain productive for the long term.
Modern crops often receive more fertilizer than they can use. While this can raise yields, it also increases nutrient runoff to rivers and boosts greenhouse gas emissions. Much of the fertilizer that is applied becomes locked onto soil particles over time, making it unavailable to plants. Heavy use of soluble nutrients can also produce “lazy” crops with smaller root systems that rely on external inputs rather than the soil’s natural reserves.
Nature shows a different path. In Canada’s forests, trees thrive in nutrient-poor soils by growing deep, active roots and partnering with soil microorganisms. As roots search for nutrients, they release root exudates—small carbon compounds that help dissolve soil particles, free trapped nutrients, and energize microbes. These processes support nutrient cycling, soil carbon storage, and overall soil health.
Research from soil scientists reviewing 36 studies across 30 crops suggests that careful reductions in fertilizer can activate these natural strategies. Cutting phosphorus by up to half increased root exudation by about 30%, with only a small 2% dip in growth. Reducing nitrogen also raised exudation, but it came with a much larger 20% decrease in growth. The takeaway is clear: optimizing phosphorus use can encourage more active roots and healthier soils with minimal yield tradeoffs.
Success depends on soil type and local conditions. Soil pH, texture, mineralogy, and moisture vary widely—from British Columbia to Manitoba, Québec, and Saskatchewan—and those differences shape how exudates influence nutrient uptake and carbon capture. That is why field trials with farmers are essential. Testing reduced-P strategies in real fields will help calibrate rates, timing, and placement to maintain productivity while improving soil function.
A practical path forward is to right-size phosphorus, monitor crop response, and foster robust root systems. With stronger roots, active microbes, and better soil structure, farms can protect water, store more carbon, and remain productive for the long term.
Modern crops often receive more fertilizer than they can use. While this can raise yields, it also increases nutrient runoff to rivers and boosts greenhouse gas emissions. Much of the fertilizer that is applied becomes locked onto soil particles over time, making it unavailable to plants. Heavy use of soluble nutrients can also produce “lazy” crops with smaller root systems that rely on external inputs rather than the soil’s natural reserves.
Nature shows a different path. In Canada’s forests, trees thrive in nutrient-poor soils by growing deep, active roots and partnering with soil microorganisms. As roots search for nutrients, they release root exudates—small carbon compounds that help dissolve soil particles, free trapped nutrients, and energize microbes. These processes support nutrient cycling, soil carbon storage, and overall soil health.
Research from soil scientists reviewing 36 studies across 30 crops suggests that careful reductions in fertilizer can activate these natural strategies. Cutting phosphorus by up to half increased root exudation by about 30%, with only a small 2% dip in growth. Reducing nitrogen also raised exudation, but it came with a much larger 20% decrease in growth. The takeaway is clear: optimizing phosphorus use can encourage more active roots and healthier soils with minimal yield tradeoffs.
Success depends on soil type and local conditions. Soil pH, texture, mineralogy, and moisture vary widely—from British Columbia to Manitoba, Québec, and Saskatchewan—and those differences shape how exudates influence nutrient uptake and carbon capture. That is why field trials with farmers are essential. Testing reduced-P strategies in real fields will help calibrate rates, timing, and placement to maintain productivity while improving soil function.
A practical path forward is to right-size phosphorus, monitor crop response, and foster robust root systems. With stronger roots, active microbes, and better soil structure, farms can protect water, store more carbon, and remain productive for the long term.
Photo Credit: gettyimages-fotokostic