This is part two of the “Below Our Feet” series. This series of articles aims to shine a light on the mysterious underground world of plant life beneath our feet. In the last article, we explored some of the secret superpowers of plants. Not only are roots the foundation of ecosystem health and integrity but they also provide a wide array of other vital services. In this article about soil life, we will have a closer look at the hustle and bustle in the Rhizosphere, the region of soil under the direct influence of plant roots.
Who lives below our feet?
On first observation, soil appears as a rather stagnant material on which we walk, grow plants, and build our homes. On closer observation, however, we can see that soil is teeming with life. A handful of healthy soil may host more living beings than the entire human population, most of them invisible to the naked eye. Ninety percent of these creatures have not even been named yet. Behind the scenes, creatures in the Rhizosphere work hard to support the rest of life. Gaining recognition as a new frontier, soil animals big and small are starting to get more attention for the essential services they provide.
Can you imagine an ecosystem more diverse than a tropical rainforest or coral reef? The Rhizosphere is home to myriads of soil animals. If you look closely, you might be able to spot some of the larger creatures living in the soil such as earthworms, ants, slugs, and mites. To get a glimpse of the smaller creatures, you will need a microscope or magnifying glass. Springtails, bristletails, and roundworms, just to name a few, are all soil animals who usually evade human perception. Together with larger, more familiar animals like moles and mice, they all do their part in bringing soil to life.
The busy life of soil engineers
Burrowing, burying, and building – soil animals are the engineers of the underground world. The channels and tunnels they dig ensure the flow of water and air, indispensable for life underground. Through their activities, soil animals mix the soil and evenly distribute nutrients within the different soil layers. In this way, they can even bring dead, compacted soil back to life. Thanks to the hard work of soil animals, plants can access all the nutrients they need and grow with ease. In return, plant roots provide soil animals with shelter, living structures, and spaces to forage for and store food.
Soil animals are also recycling champions. When a plant dies on the surface, they break up the dead plant material and make new soil with it. Soil animals even recycle nutrients by ingesting organic matter. For example, earthworm “slime” helps soil particles stick together and thereby prevents erosion, while earthworm castings are packed with nutrients that are easily available for the next generation of plants. Tirelessly, soil animals like the earthworm propel the endless cycle of plant growth, decay and soil formation. As consumers and decomposers, they play a key role in shaping ecosystems both above and below the ground, keeping them healthy and productive. In many ways, the Rhizosphere acts as the stomach of the Earth – consuming, digesting, and cycling nutrients and organisms.
How to help our essential workers in the soil
Healthy soil life is, in essence, the foundation of life below and above ground. Often overlooked, soil animals facilitate the movement of water, air, and roots – they are instrumental in nutrient cycling and soil formation. Whether it is for your own garden or for the ecosystem at large, adopting land care practices that support soil animals is beneficial for all. Some of the practices that support soil animals in the Rhizosphere include:
- Maintain continuous living roots systems by avoiding tillage and soil compaction through machinery.
- Increase soil organic matter with natural inputs such as compost, leaf mulch, wood chips or coarse woody debris.
- Increase soil biodiversity by eliminating pesticides, herbicides, and synthetic fertilizers and planting native species.
- Cover the soil as much as possible year-round by planting perennials and leaving plants on the ground as they die for green manure. Native cover crops are great for this!
Soil life is enriched by the introduction of nutrients and useful species like the earthworm. You might already use compost to attract these essential workers into your garden. Compost is packed with essential soil workers. If trees need to be cut for housing or safety reasons, consider leaving them to decompose naturally. As trees decompose slowly over time, they gradually leak nutrients into the ground, attracting many soil animals to the area. In addition, dead trees provide housing for other creatures such as nesting birds and bats.
The idea is to put at least as many nutrients back into the ground as we take out. This is especially important when it comes to ecosystem restoration. Many places on Mayne Island are deprived of nutrients due to years of farming and logging. Therefore, natural nutrient recycling through decomposition is crucial to regenerate the Rhizosphere and allow the soil animals who live there to perform their essential work.