“Man – despite his artistic pretensions, his sophistication, and his many accomplishments – owes his existence to a six-inch layer of topsoil and the fact that it rains.” — Paul Harvey

It's fascinating to consider how much time and money our nation spends on trying to find topsoil and water on the moon and other planets. How many billions have we spent? Yes, we are looking for life, but a significant part of that quest involves searching for life in the soil, specifically in the form of microbes.

In my last blog, I asked you if you buy organic food. I explained the progression of my experiences and beliefs about organic food production. A conversation about the differences between organic and conventional food production has to start with a basic understanding of soils and microbes.

I recall a scene in the 2015 movie “The Martian” where Matt Damon plays an astronaut/botanist who must figure out how to amend the Martian topsoil to grow enough potatoes to keep him from starving until he can be rescued. Do you remember his solution?

This scene reminds me that there's a difference between dirt and soil. It's hard to grow things in dirt because dirt lacks the essential soil microbes necessary to support plant life. I grew up on a first-generation farm. My parents were urban-raised transplants who had to figure out how to evaluate and amend dirt to make it into healthy soil. This was well before YouTube, so it took much longer back then as all we had was the county extension office, 4-H classes, and the help of a knowledgeable neighbor. It took us years to figure out how to grow vegetables successfully.

The importance of soil and microbes

Soil is a dynamic and complex ecosystem teeming with life. Unlike inert dirt, soil is full of organic matter, minerals, and a rich community of microorganisms. These soil microbes, including bacteria, fungi, and protozoa, play a crucial role in the health and fertility of soil.

Microbes are essential to the growth of plants for several reasons:

1. Nutrient Cycling: Soil microbes break down organic matter, releasing nutrients in forms that plants can absorb. For example, nitrogen-fixing bacteria convert atmospheric nitrogen into a form that plants can use, which is vital for their growth.

2. Disease Suppression: A diverse microbial community in the soil can suppress plant diseases by outcompeting or inhibiting the growth of harmful pathogens.

3. Decomposition: Fungi and bacteria decompose organic matter, returning essential nutrients to the soil. This process also improves soil structure and increases its ability to retain water.

4. Symbiotic Relationships: Many plants form symbiotic relationships with mycorrhizal fungi, which extend the plant's root system, improving water and nutrient uptake.

You may have experienced the frustration in your own garden of trying to grow plants in dirt. The plants die even though they seem to get adequate water, and you don't know why. Did you amend the soil? Do you have the right nutrients and microbes?

In many newer suburbs in Denver, the HOA requires home builders to install grass in the front yards before they can sell a new home. The backyards are left for the new homeowners to do after they move in. The home builders slap down Kentucky bluegrass sod on the hard dirt as cheaply and quickly as possible. No compost, topsoil, or other amendments are made. These yards struggle each year to grow the 'crop' of Kentucky blue successfully. Many homeowners water too much, fertilize too often, pick up the lawn clippings that go to the dump, cut the grass too short, and don’t amend the soils adequately, then wonder why their trophy front yard lawn suffers so much each summer.

Healthy soil teeming with microbes ensures robust plant growth, improved crop yields, and sustainable agriculture. This complex interaction between soil organisms and plants forms the backbone of both organic and conventional farming methods.

It's essential to understand how soil microbes respond differently to organic and conventional inputs like fertilizers, herbicides, pesticides, and fungicides. I’ll be examining these inputs in the coming blogs.

Please share what you know.

Soil 101: Dirt vs. Soil

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