Microscope becomes key tool for farmers

Allison Squires uses an OMAX 40X-2500X LED digital trinocular compound microscope to check a sample of vermicompost to make sure it has a high diversity of biology before she uses it to make the compost tea with which she will coat seeds this spring. | Cody Straza photo

Organic producer uses instrument to assess soil health and identify the good and bad micro-organisms that are present

The microscope is becoming an essential tool to brew up a good batch of compost tea.

But composting or not, it should be part of every farmer’s tool kit, said Allison Squires of Upland Organics near Wood Mountain, Sask.

“I have found the microscope to be one of my most useful tools that we use to measure the health of our soils. The only soil health tools that we value higher are a shovel and a set of infiltration rings,” she said.

“When I first started with the microscope, I wasn’t composting at all. I used it to assess the soil health across my farm to see where we were at and that’s what led me to composting.”

Squires spoke about on-farm composting with organic producer Rob Wunder at the Advancing Organics Online Conference and Trade Show held March 25-26.

“I use the microscope to look at the soils during the growing season, as well as check all of our different types of compost and any extracts and teas that I make from them,” said Squires.

Peering through her trinocular compound microscope, she analyzes three categories that she termed:

  • The Good: “Bacteria, fungi, protozoa, nematodes — these are all things that are easy to identify. I’m assessing not only how many of them there are, but also the different types of diversity of them because you need a bunch of different species within those groups to make the soil food work properly.”
  • The Bad: “Things you shouldn’t find in your soil like different bad types of bacteria or problematic types of fungi that we look for to make sure they’re not there, like root-feeding nematodes.”
  • The Ugly: “I call them the ugly because I don’t know what they are. There’s lots of things that I’m still learning how to look for and that’s where my peer network comes in to help me.”

In 2018, Squires completed an online course where she used a common light microscope to assess the soil biology in every field across her farm.

“It took a long time, but I found it so valuable. This assessment now serves as our baseline going forward,” she said.

During this initial assessment, it was exciting to find a relatively healthy bacterial and fungal population.

“However, I also discovered that we had very low amounts of protozoa, to the point that I had trouble finding any,” she said.

As a result, the past two years have been focused on bringing back these organisms in order to re-establish the soil food web and allow for efficient cycling of water and nutrients in the soil.

This kickstarted the journey into composting, specifically the vermicomposting method using worms (red wigglers), which is less time consuming and allowed her young children to participate in adding kitchen scraps to the mix, and can be continuously and easily harvested.

“I use the microscope to analyze the biological component of the compost since that is what I am most interested in and the main driver behind why we are using the compost on our farm versus the nutrient content of the compost,” she said.

“We want to be able to do a lot of our own assessments here on the farm so we can have results quickly and a better understanding of what we’re overseeing. That’s why we invest so much time and effort into learning these techniques is because that is important to us to have it right here on the farm.”

“The microscope helps me target my problem areas and address those specifically. So when I’m brewing my extracts and my teas, I’m able to brew those teas to be more exactly what I need to add to my soil. For example, if I needed to be higher in protozoa, there are certain things that I can add to my tea to drive it higher. Then I check with the microscope to make sure that those populations are higher in my tea and then I know for sure that what I’m adding is what the soil needs,” she said.

Learning to use the microscope took some study time and commitment, and Squires continues to enrol in webinars and courses.

“It comes easier with practice but I believe it’s something that any interested farmer can learn to do on their own farm. The basics of what to look for (fungal strands, bacteria) are easy to start to learn how to recognize and as farmers, we can certainly learn a lot from keeping our eyes on these two groups of organisms,” she said.

There are also more YouTube presentations available with content in the regenerative ag space.

“You don’t necessarily need to take a large course like what some of us have done, but I still do recommend it just to get the basics down. But I think if you were looking to just get started and if you were curious of what was there and what you needed to improve on, you could start with some of the free resources that are out there already,” she said.

There are also several internationally established peer networking groups that use the microscope to exchange photographs and information.

For more detailed analysis, a growing number of labs will offer expertise.

The microscope also shifts attention toward the biology of the soil rather than the physical and chemical parameters of the soil.

Too often, she said, the standard soil analysis package is focused on the physical and chemical characteristics, while completely excluding the biological aspect.

“In reality, the health of the soil biology is what ultimately drives the availability of nutrients and water to the plant and should always be included when we are doing a soil assessment.”

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