Soil Life

“We know more about the movement of celestial bodies than about the soil underfoot”                                                          

Leonardo Da Vinci

Beneath our feet lays an amazing food web that is so important to us and for the planet, yet it is so often forgotten and mistreated. When we look at our soil we may see many signs of life- worms, ants, slugs, ladybird beetle larvae, centipedes and slaters. In actual fact, good soil is absolutely teeming with life that can’t be seen with the naked eye, in a soil food web that is complex and fascinating. Not only does this support plant life, but it is now coming to our attention how important this microbial life is to our survival and to our health.

In our soils there is a whole world of tiny, microscopic organisms that can only be seen using sophisticated and expensive optics- bacteria, fungi, protozoa, nematodes- in numbers that are quite staggering. A teaspoon of good garden soil contains a billion invisible bacteria, metres of invisible fungal hyphae, several thousand protozoa, and a few dozen nematodes. The health of our living soil, where we grow our food, is arguably the single most important factor in the sustainability and health of this planet and that of all of us creatures living on it.

Sadly, humans have recklessly devastated soil microbiota essential for plant health through overuse of certain chemical fertilizers, fungicides, herbicides, pesticides, failure to add sufficient organic matter (on which they feed) and heavy tillage.  These soil microorganisms- particularly bacteria and fungi, cycle nutrients and water to plants, our crops, the source of our food, and ultimately our health.

These soil microorganisms do much more than nourish plants. For millions of years plants have been forming symbiotic associations with fungi that colonize their roots. These fungal filaments not only channel nutrients and water back to the plant cells, but they connect plants and actually enable them to communicate with one another and set up defense systems. This may all sound a little bizarre, but there have been experiments done to prove that through the mycorrhizae, plants under pest attacks can communicate this to healthy plants, which allows them to activate their defenses before being attacked themselves.

Another amazing fact is that plants control the nutrients surrounding their root zone by manipulating the chemicals secreted by their roots. In healthy soils, plants have the ability to attract specific fungi and bacteria and control their numbers that are attracted to the root zone.  Different fungi and bacteria produce different nutrients,  so during different times of the growing season, the plants attract the ones they need depending on the needs of the plant. So rather than the plants sitting idle, they are actually in control of the nutrients available to them.

I have always believed that gardening is good for your health and state of mind, but there is now evidence that these soil microbes contribute to the elevation of mood when in the garden. Most of the research has focused on Mycobacterium vaccae, a harmless soil microbe found in soil and unwashed vegetables. Studies have found that it activates the release of brain serotonin leading to reduced stress-related behavior, resulting in less depression and anxiety and increasing feelings of wellbeing. More interaction with a range of soil microbes results in increased functioning of the immune and nervous systems. There are so many species of soil microorganisms that there is no end to what the possible benefits could be.

All of these amazing organisms need energy to survive, the majority getting this energy in the form of carbon. Carbon comes from organic material supplied by plants, waste products produced by other organisms, or the bodies of other organisms. Therefore, one of the most crucial things that we can do for our soils and the planet is composting. Returning organic material back to the earth, supplying the life in the soil with food, is something we all can do for the benefit of all life. There is also much research into “bio fertilizers”, where key bacteria and the right species of fungi can be grown and added to the soil. As the soil improves, plant health improves, eliminating the need for pesticides, synthetic fertilizers, herbicides and fungicides. Soils will retain nutrients in the bodies of soil food organisms instead of  them leaching out. Your plants will be getting nutrients in the form of each of particular plants wants and needs so they will be less stressed. Your plants will have natural disease prevention, protection and suppression. Your soil will retain more water.

So we all should begin to explore and appreciate our soils and wonder at the complex web of life that it contains. If we all do whatever we can to enhance the soil that we walk on, embracing it rather that taking it for granted, we will be making huge steps in creating an abundant, fertile world.