Soil School: What can a soil pit teach us?

Whether you’re talking to financial advisors or agronomists, having knowledge and data about your farming operation is key. Digging a soil pit is a great way to see what exactly you’re dealing with below the surface.

On this episode of the Soil School, we are joined by Ken Wall, a grow team advisor with Federated Co-operatives Ltd. He takes us through the ins and outs of soil pits including how far down you need to dig, what you’re looking for, and what a soil pit can teach us.

Farmers should consider digging a soil pit in each different soil region within the farm. Wall says to look at the soil maps and coordinate sites from there; probably one or two pits per farm is a good start.

When digging the pit, dig down about 18 inches in most cases. We often think of soil in soil-sampling depthss — 0 to 6 inches, 6 to 12, and 12 to 24 inches, however, these numbers are just guidelines and the actual depths will be determined by the A and B horizons.

“You’re A horizon is where you’ve got all your organic matter. That’s the horizon that was formed by your climate, by the precipitation and the amount of different vegetation that you had growing here since the last ice age, so it’s really important to know where that depth is,” explains Wall. “So if you’re taking a (soil) sample zero to six, and you’ve only got an A horizon down to four inches, you’re probably going to over or underestimate the amount of organic matter you’ve actually got in that horizon.”

Once you’ve exposed the right cross-section in the soil, this is where you can learn a lot about the contents of your soil from the pit including sodium concentration, structural changes and more. Wall shares that it’s important to know this information as it can have a large impact on your seeding applications come spring time.

Watch the full episode below and for all of the Soil School episodes, click here.