The Agronomists, Ep 43: Laura Van Eerd and Scott Gillespie on soil health gains from cover crops

University of Guelph sustainable soil management professor Laura Van Eerd

Using cover crops in a grain rotation can help achieve several goals: decreased soil erosion, decreased loss of nutrients off the field, increased weed suppression, and more. The research suggests that incorporating cover crops in to a grain farm increases crop yield, too.

To discover how the tool can be used — yes, even in Western Canada — we go to Dr. Laura Van Eerd, professor of sustainable soil management at the University of Guelph Ridgetown Campus, and Scott Gillespie, founder of Plants Dig Soil Consulting, to talk about cover crop impact on soil health, best uses, and more.

Catch a new episode of The Agronomists every Monday night at 8 pm E!


  • What are the goals for a cover crop? To see changes, or improvements in soil health over time… There should be a return on investment, within a year or two…
  • Wind erosion is a huge problem where Gillespie’s at (The Palliser Triangle) They have WIND
  • Other cover crop goals: fixing N, weed control, nutrient cycling
  • “Roots not Iron”
  • You might just think that your soil is “just sand” or “just a type of soil” and that it’s not great, but there are a lot of nutrients leaving that field
  • In the early years, Van Eerd was quantifying how much nitrogen was staying in the system using cover crops
  • Under irrigated practices, Gillespie figures that if moisture is a concern, there’s no reason not to use a cover crop, given irrigation is used conservatively. If you don’t have enough moisture in a dryland situation, pretty hard
  • If you’re no-till, and you’ve got good soil armour, but not enough moisture, no point in growing something
  • In what year did the soil health benefits start to appear (Q to Van Eerd)? At the beginning it was hard to secure funding to perform all the analysis
  • Like a true soil scientist, she also says “it depends”
  • Just because there’s a lot of interest doesn’t mean that researchers can hop to it
  • The yield difference… corn and long-term cover crops
  • There could be nitrogen penalties too, when using a cover crop. Food for thought.
  • N can be released, and tied up, as it undergoes cycling
  • “I want to validate the work I’m doing, what’s the best way to measure soil health”
  • Gillespie doesn’t use any soil health tests, yet
  • Is your soil crusting? Is it holding water?
  • Van Eerd says just to soil test and measure OM, CEC, soil pH, P and K and start there
  • There are existing tests, but the results can be hard to decipher
  • Observation can still tell you a lot
  • From a soil biology perspective, how long is too long without living roots in a system?
  • In the Variable Rate sphere there could be an option to do three species across a field, as a prescription
  • How much top growth is needed in the fall before a frost, to say that the cover crop has done any good?
  • Capture that carbon through photosynthesis, so you can feed the soil microbes
  • “Some is better than none” as long as you’re not spending too much $$$

Wake up with RealAgriculture

Subscribe to our daily newsletters to keep you up-to-date with our latest coverage every morning.

Wake up with RealAgriculture