Fungi play a very important role in the soil food web. The aerobic, filamentous hyphae act like a grocery delivery service for plants. A plant indicates what nutrients it needs and the fungi seek out those nutrients in the surrounding soil! The fungi is rewarded with plant exudates (sugars/carbs/proteins) that it requires. A wonderful symbiotic relationship!
Not only do fungi help bring nutrients to the plant, but it also builds soil structure and increase the water holding capacity in the soil as well.
How Fungi Help Build Soil Structure
Fungi work with bacteria to link together the microaggregates formed by bacteria into macroaggregates. These structures help produce water and air infiltration points ensuring aerobic soil conditions. They also make pathways for roots to drill into.
Fungal enzymes are best at decomposing complex foods (C:N > 60:1). You may have heard that wood chips, leaves and straw are ‘fungal foods’.
How fungi help plants thrive
Fungi build large networks that eat a lot of nutrients. These nutrients are stored in their hyphae.
The amount of nutrients they hold in the hyphae, exceed the amount of nutrients fungal predators need. So, when fungi are eaten (by nematodes or microarthropods), the extra nutrients are expelled in plant available forms.
Fungi also colonize around the roots of plants (remember the symbiotic relationship I mentioned above?). They, along with bacteria, fill up all of a plants ‘infection sites’ along their roots. This prevents pests and diseases from gaining access to the plant and harming the plant.
Fungi are fragile
Fungal hyphae are very fragile. Any soil disturbance can damage or kill the fungi. This breaks down the soil food web and can lead to imbalance. When the soil food web is out of whack, plant vigor and health suffer. It also offers pests and diseases a chance to take hold.
Soil disturbances include tilling, adding fertilizers, using herbicides and compaction. Unfortunately for fungi, these are common and accepted practices in agriculture today.
3 easy ways you can help fungi thrive
Luckily small changes to how you manage your yard can help fungi recover and thrive.
- Start practicing No-Till in your garden
- Apply biologically active compost to your soil rather than inorganic, salt-based fertilizers.
- Keep your soil covered, even in winter. Mulch with spent straw or leaves.
When we take a step back and look at our gardening practices, we can make small changes that will support the food web and save us time and money!