The Human Body and the Soil: An Analogy for Understanding the Soil Microbiome
To help us understand the importance and complexity of the soil microbiome (the living part of the soil that is composed of soil microorganisms), organic researcher Elias Bloom (a member of the Casteel lab at Cornell University) suggests beginning with an analogy. “The human body has more microbiome cells than it does human cells,” Bloom explained at a recent eOrganic webinar. Over 10,000 different species of microorganisms live in and on the human body, and they can have broad implications for human health. Essentially, a healthy human body is driven by a healthy microbiome.
Compare this analogy with the soil: one teaspoon of soil may have over one BILLION microorganisms living in it. And in just one small teaspoon of soil, there are often over 10,000 species of microbes, similar to the number of species found in the human body. Since microbes are involved in everything from water-holding capacity to promoting disease resistance, one begins to see that what a farmer does everyday can have serious effects on current and subsequent crops.
The Importance of the Soil Microbiome
The living portion of the soil is a primary driver of nutrient cycling, a pillar of healthy soil structure, and can enhance resilience to climate change and pests. The microbiome also helps break down pesticides, toxins, and excess nutrients. It is generally understood that high soil microbe diversity promotes pest suppression and that organic land tends to have higher soil diversity than conventional fields. Still, in some cases increases in diversity can mean increases in plant pathogens. For farmers and researchers, understanding which farming practices result in a ‘healthy microbiome’ and translate to positive effects on crop production, is complex.
