The more I learn about the soil food web and plants, the more I am in awe of the intricacies of the vibrant life that goes on below ground and the intelligence of plants. It’s easy to dismiss what we can’t see - the soil food web beneath ground and what we can’t relate to - the curious intellect of plants even though they don’t look like us with a central nervous system and eyes to see and ears to hear. These parts of nature are just as alive as any animal in our ecosystem.
Often times I feel overwhelmed trying to understand the complexities of soil and the relationships between the microbial life beneath ground and what grows above.
A good place to start though, is understanding the difference between soil and dirt.
Soil is alive! It’s much more than just minerals and organic matter. Just 1 tsp of topsoil can contain 1 billion microbes and 10,000 different species! That’s pretty hard to wrap my mind around. All of these, just like us, require oxygen and food to survive. Thriving soil is light and porous - it allows for plenty of oxygen to be present, which supports life. The soil food web is made up of bacteria and fungi and inhabited by organisms such as protozoa, nematodes and more commonly - the earthworm. All of these feed off of roots being in the ground.
Dirt is barren and lifeless. It’s made up of silt, sand and clay and contains anerobic bacteria which don’t require oxygen. As soil becomes compacted, oxygen particles are compressed out, suffocating the life of the soil food web and organisms that need oxygen to survive - degrading the soil into sterile dirt.
Preserving the oxygen, fungal networks and all of the life in the soil is our highest priority.
Supporting life below ground by keeping roots in the soil (providing food) and disturbing the soil as little as possible (providing oxygen) are essential to a thriving ecosystem below ground.
One of the biggest contributors to compacted soil is tillage.
You may relate compacted soil to inhibited root growth but the main problem is lack of oxygen. Tilling the soil only temporarily “aerates” the first few inches of soil while compacting everything underneath and ripping apart all the intricate fungi and organisms in the soil. This prevents access to nutrients below and encourages our precious topsoil to be exposed to erosion and run off. Furthermore, it encourages the soil to remain in a bacterially dominated state - not allowing fungi to do it’s important work of nutrient cycling as well as encourages weeds to take over. Very delicate fungal pathways make up living soil and are essential for efficient mining and cycling of nutrients. Intricate nutrient exchange happens between the plant roots and the bacteria and fungi present in the soil.
It’s a tough subject to write about in such a short space because it’s so vast and complex! Soil science even now is still at it’s infancy. We have learned much but really have only scratched the surface of the marvel that lies below ground and of the magnificent workings of plants!
If nothing else, the main takeaway is that even in what we can’t see or understand - there are vital pieces to the puzzle that comprise life. Prioritizing eating food that comes from a place where the soil is held in high regard and practices are in place that support the diverse array of a thriving ecosystem.