Soil Biodiversity

Healthy soil is made by a healthy soil biome! Animals, bacteria, and fungi in your soil all interact to make sure that lots of organic matter is made regularly and spread throughout your garden. Supporting your soil ecosystem will also improve your soil texture, reduce erosion and improve plant growth.

The best way to help your soil is to:

• Regularly add organic matter to the soil in the form of mulch or compost
• Avoid leaving the soil bare for long periods of time. Heavy rains will wash away organic matter, leaving dense and sticky clay that is difficult for most organisms to live in. Grow groundcovers or practice interplanting to protect your soil
• Avoid using general pesticides which may kill biodiversity as it is washed into the soil

Some common things you will see in your soil are:

Earthworms

Often found in burrowing in true ground soils, earthworms are key to keeping soil porous, fertile and well-mixed with organic matter. Earthworms eat decaying organic matter like leaf litter and dead roots, and their waste product, known as worm- or vermicast, have nutrients that plants readily absorb. The tunnels they dig also creates drainage and aeration in the soil, with the earthworms creating and dropping vermicast along the way.

Earthworms will naturally appear in true ground beds as more plants and organic matter is introduced. Keeping the soil cool with organic mulches, regularly watering your plants, resolving waterlogging and building a worm tower will encourage earthworms to settle in your garden.

Do note that earthworms used for vermicomposting are different from worms found naturally in true ground. Vermicomposting earthworms are adapted to living in pure compost and may not survive in Singapore’s naturally clayey soil. Likewise, wild earthworms from your garden are unlikely to survive living in your vermicomposting setup!

Fungi

Mushrooms are the fruiting bodies of fungi, and while they look delicious it is generally not recommended that you eat them. The tropics has a massive diversity of fungi, some of which can be poisonous. It is better to be safe rather than sorry and leave them be!

Fungi are important decomposers and are key to breaking down woody plant material into nutrients that can be taken up by plants. Soil, compost, and organic mulch that has a lot of woody material will have more mushrooms appearing, particularly during the wet season, and should not cause alarm. However, mushrooms appearing in pots can be concerning as they generally need moist environments to survive; a plant pot with many mushrooms could be overly moist due to poor drainage, which may eventually lead to root rot for the plant.

Millipedes

These many-legged creatures are often found in parks and gardens that use mulch and compost with a lot of woody material. They are harmless, but they can produce an unpleasant smell if startled.

Another decomposer, millipedes eat decaying wood and leaf litter. Their eggs can sometimes be brought into a garden via unheated compost or in woody mulch. Adults usually appear during the wet season.

Millipedes are generally not considered a pest, although their waste products can cause burns on young leafy vegetables if they are present in a garden in high numbers. Millipedes can be removed by hand, and their population controlled by using less woody material in the garden.

Download a Research Technical Note on Millipedes in Singapore here.