702 Soil Carbon and Tillage

May 21

Podcast Intro

I've been doing a bit of digital data cleanup lately. This was inspired by some episodes over the winter from the GardenFork podcast. Eric talked with Rick about tightening up your security and and getting rid of things that you don't need floating on the internet anymore. I got looking through my website and my old Medium posts (linked at the bottom of the Media archive). It’s been surprisingly encouraging. Most of what I wrote years ago still aligns with how I think today. It was the same with LinkedIn. I scrolled and scrolled and scrolled until I got to my oldest posts. My perspective has evolved, but the core ideas are still there.

So, if you're new here, let me introduce myself. My name is Scott Gillespie and I'm an author and independent agronomist rooted in the Canadian Prairies focusing on Climate-Smart Agriculture. I share science-based practices that benefit the planet while contributing to the profitability and resiliency of those who farm it.

The content of this podcast episode is available in many formats.
It's the same content on each, just in different forms.

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Business Highlight

Something I realized years ago was that if I've done my job right over the winter, I won't be super busy come spring time. In other words, if the plans are in place and I've got all my record keeping apps setup properly, I shouldn't be scrambling with recommendations or spending hours keeping track of everything going on. That's how it's been this spring. The farms are busy, but I'm not. I'm able to respond to questions, go check fields to monitor progress, and keep up with everything without working long days. In fact, it's allowed me to spend some time on my own garden.

Selling consulting only services is a tough sell to farmers that are used to "free" advice from people that sell products. I'm just not a good product salesman, so I'm glad to have made this work. I have some room for in-season support or winter planning. If you're looking for an independent advisor, please get a hold of me.

Featured Article

I'm pleased to highlight my first article in Better Farming Prairies. As I said in the intro, it was interesting to discover that ten years ago, when I was writing in Medium, I was submitting to publications on that site. After seven years of podcast production and writing a book, I have achieved the goal of writing for a larger audience.

The article is titled "Soil Carbon & Tillage: Eat Your Cake and Have it Too". In the article I differentiate between deep tillage that happens on a regular basis and strategic tillage that is there to solve a particular problem. This could be in breaking up compaction, resetting nutrient or pH stratification, or incorporating amendments like manure or compost.

I also go in depth about POM and MAOM. POM is Particulate Organic Matter. This is the stuff that still would look like what it was when it was alive, it's just been ground up over time and is now less than 2mm. MAOM is Mineral Associated Organic Matter. This is the stuff that is made up of small molecules that are - you guessed it - tied to the minerals of the soil.

Which is these does tillage most affect? Which of these stick around longer? You'll have to go to the article find out!

https://www.betterfarming.com/flippingbook/better-farming-prairie/2025/april/26/index.html

Interesting Articles I've Come Across

Polycrops: Challenges, Triumphs and Valuable Lessons from Beef Producers

Last month's episode called "No Cows? No Problem" argued that if the economics of taking a field out of annual cropping and putting it into an annual forage for grazing made sense, then you should go for it. Otherwise, if you don't have cattle or don't have them nearby, don't worry that you are missing out on soil health benefits by not having them in your rotation. This article goes more in-depth on the practices that are working for producers across the prairies.

A few of the lessons I saw from this:

1) The shotgun approach - a whole bunch of species all planted at once as a cocktail cover crop - can work when you are just trying to learn what the soil needs. After that, a tailored blend for specific fields, or parts of fields is best.

2) Weeds happen. This was noted in the study referred to last month. They add unintended diversity and need to be monitored. One producer noted that it wasn't until she was using polycrops for a few years that the weeds started to show.

3) Soil health benefits are not clear right from the beginning. All producers expect to see results in the future and look to short term economics first. They still need production now to pay the bills, but they hope to see the benefits accrue in time.

https://www.beefresearch.ca/blog/polycrops-lessons-from-beef-producers/

Less intensive farming works best for agricultural soil

The headline seems like a no-brainer, and I almost skipped it, but it lines up very will with the article I wrote on tillage. The less intensively you till the soil, the more organic matter builds up, and the better it's function overall. Perennial phases are nice to have as well, but the economics of those are hard to make work in every area. Interestingly the best indicator of soil health was soil carbon. Organic carbon is approximately 60% of organic matter content, so it appears we have one of the best indicators of soil health already.

https://www.sciencedaily.com/releases/2025/04/250425230526.htm

Soil Organic Matter in Natural Ecosystems vs. Cropped Fields: A Misleading Comparison

This is another deep dive by Dr. Andrew McGuire and it doesn't disappoint. He covers one of my favourite topics: imports and exports. In a natural system, there isn't much that leaves the land. Pretty well everything lives and dies there. Sure, they move around. But someone may eat and poop in one area and another may do the opposite. Grazing systems are close to this but the meat leaves the land. The export is much slower, but it still affects the system over time.

https://csanr.wsu.edu/soil-organic-matter-in-natural-ecosystems-vs-cropped-fields/

OFC-210 Soil Health & Fertility in Organic Field Crops

This is a course that I worked through on the Organic Agronomy Training Service (OATS) website. I'm on a listserve that recently posted that this course, and all the other ones they offer, were going to be free from now on. Now, I know your first question is: What's a listserve? It's an old-fashioned email distribution system that allows anyone to send something out to a list of people. If you want on the list, get a hold of me and I'll tell you how.

Back to the course. I have found this to be an excellent introduction to working on fertility plans for organic growers. If you're organic-curious or just of a regenerative mindset, this will be very helpful to you.

Key takeaways for me are:

1) You need to watch your imports vs your exports! Just like the article above by Dr. Andrew McGuire and like what I've been saying for years, you can't take and take and take and expect the land to regenerate. It needs nutrients & carbon put back into it because of all we take out of it when we export what we produce.

2) Foliars, biologicials, and humics can have a place in your fertility plan, but they are not the foundation of it. The course instructor directly warns that are many, many "snake-oils" out there. These are products that have no substantiated claims and are often marketed as miracle cures or something that the mainstream academics or companies don't want you to know about. The problem is, as one of the farmers in the videos says, there are some that work. So you need to do on-farm trials and really test their claims.

3) Soil balancing is not proven and often costly. The topic is handled well because there are many people (maybe you) that believe we need the right ratio of nutrients, usually targeting calcium and magnesium, in the soil for the system to function properly. Some even claim that weeds will disappear when the right ratio is achieved. As a professional that needs to be able to back up my recommendations, in court, if needed, I have to follow the scientific consensus. Right now I do not see the evidence for soil balancing, but I'm always watching new research to see its fit.

https://courses.organicagronomy.org/p/soil-health-fertility-field-crops-ofc-210

Omnivorous: How literary scholar David Shields, AM’75, PhD’82, came to rediscover dozens of forgotten crops and preserve Southern culinary heritage.

This final article was sent to me by a friend from the GardenFork podcast. Nicole is a writer and photographer and also co-hosts the show occasionally. She actually interviewed me on the podcast once about my book. Eric was supposed to be there but he was having technical difficulties. Anyways, she came across this article where, as the subtitle says, a literary scholar has found his retirement job in rediscovering the connection between place and food. I'd never thought of this before but an old family recipe may not work as well today because the ingredients we have either don't exist or what we do have doesn't create the same flavour. Anyways, it's interesting reading. It also gets me thinking: What will my retirement job be?

https://mag.uchicago.edu/arts-humanities/omnivorous

Podcast Outro

Thanks for listening! If you found something thought-provoking—or want to share a piece I should check out—get in touch. On Spotify, you can leave a voice message. On other platforms, just follow the links in the episode description to get to my website — www.plantsdigsoil.com — and send me a message through the contact page.

While you’re there, be sure to check out my book: Practical Regeneration: Realistic Strategies for Climate-Smart Agriculture. I keep the podcast free, and if you’d like to give a little back, buying the book is a great way to do it. Unfortunately, with the looming Canada Post strike I can’t economically ship it to anyone in Canada now. Normally, I can mail it to you for same price as retail: $28 (GST & shipping included). I can do this because there's no bookstore margin. I just put some of that margin towards the shipping cost and still make my authors royalty. I have no idea how long it will last so if you are listening to this later you might be able to order it direct from me when service returns.

If you're local I just ask $20 when we can meet in person. It's also available in some local independent bookstores (check the listings on my website). Worldwide, it’s available through major booksellers or directly from the publisher. Print-on-demand is a bit pricier due to courier costs, but that’s the tradeoff for global distribution.

If you need agronomy help—whether you're on the prairies or not—get in touch. All my pricing is listed transparently on the website. I can work in person, online, or a combination of the two. If you're not a farmer but your organization needs support for a specific project, feel free to reach out through the contact page. I have put together many custom packages over the years and I'm sure we can come up with something that works for both of us.

And of course, you can always help me by sharing the episode directly with someone who might enjoy it or post to your social networks.

Here’s to growing more, believing less, and always digging a little deeper.

Scott Gillespie