• Laboratoire des sols
  • Université de lorraine

Garden management tips for soil biodiversity



Promote the diversity of habitats to promote biodiversity

To meet the needs of soil organisms, it is necessary to allow them to live in places corresponding to them (food, protection against cold, drought, predators, etc.) such as: Pile of branches / Small pile of stones / Tiles / bricks / Pile of leaves
Leaving such habitats in your garden is like creating hotels for soil organisms to accommodate and protect them. It is also interesting to avoid leaving the ground bare by leaving living or degraded plant cover (mulching) on ​​the ground, for example; this cover can limit soil erosion or its drastic drying out, and make the environment better for the survival of biodiversity. In addition, covering the soil at the foot of a plant helps retain water in the soil (less evapotranspiration) and therefore offers more water to the plants.


Why mulch your soil?

If you cultivate your soil, or if you install ornamental plants or an orchard, it is preferable to cover the soil in order to protect it. But what type of mulch to use?
The most interesting thing initially seems to be to use the organic matter available on site (at your place or at your neighbour's). Cover your soil with the dead leaves of the various trees in your garden, pruning remains of crushed branches or mowing.
Think of the acidity of the materials used: for example, cedar leaves have the particularity of being very acidic and difficult to decompose, the leaves will remain on the ground for a long time without being degraded, like those of the plane tree; bay and chestnut leaves are a little less acidifying; hazelnut and linden leaves, on the other hand, are very easily decomposed and earthworms are also fond of them, helping them to disappear in a few weeks and providing nutrients for the soil and plants. Grass clippings also decompose very quickly provided you avoid heaps that can suffocate organisms. The compost from your composter is also an interesting organic element because it is rich in nutrients and at the same time can serve as food for organisms.
Pine bark or coconut fiber also tend to acidify your soil. The best cover to install on the ground remains a mixture of different types of organic matter (diversity) to protect the ground, maintain humidity thanks to a slow degradation of the material and attract scavengers and micro-organisms (bacteria and mushrooms) which will more or less slowly recover the material on site.

Valorize your organic matter on site

The soil fauna includes many detritivores (which feed on organic waste) which are just waiting to recover your organic matter for free. So why not compost in your garden? Valuing your organic matter on site has various significant interests:
Increase in the diversity of organisms by attraction (presence of scavengers but also of predators that regulate populations).
Creation of a natural fertilizer for your soil (maintaining and stimulating its chemical and physical fertility).
Restoring the cycle of matter and a micro-ecosystem within your garden.

Restore ecological corridors on the ground (soil corridors?)

By observing your garden you observe groups of habitats or heaps of food for biodiversity scattered all over the place such as a composter which is a heap of food, a heap of stones which provides a habitat, a tuft of dead leaves which is a habitat and a heap of food at the same time.
An ecological corridor is a passageway that allows wildlife to access these different habitats, this being necessary for the reproduction and survival of organisms in the face of a variable climate from one season to another and predators. Ecological corridors in the city are limited because many facilities prevent the free circulation of soil organisms, such as a low wall between two gardens, a paved path in a park or a mineral path in a garden. Thus some species find themselves compartmentalized and cannot move from one place to another, which causes ecological discontinuities. This can be problematic when on one side of a wall in one garden there are many predators and in the other garden on the other side of the wall crop-destroying species. The food web is then broken and the two gardens can be ecologically unbalanced.
It may then be interesting to favor plant hedges and fences between neighbors to allow the circulation of soil organisms. Within your own garden, it is possible to encourage the movement of species by avoiding the creation of impermeable areas (asphalt, rocky or paved, etc.) which divide the garden into several parts. The installation of wooden planks in the paths, or leaving the paths in grass, makes it possible to create corridors accessible to the soil organisms allowing them to move freely.

Adapt your garden management to promote biodiversity as a whole

Your garden is not only a refuge for soil biodiversity, it is also a place where many other species can interact such as spiders building webs on different supports, flying insects, birds, slow worms, lizards or hedgehogs. It may be worth trying to attract these predators to your garden in order to balance the ecosystem and allow them to limit populations, thus re-establishing food chains. For this you can install:

- Insect hotels that attract insects some of which are parasitoids and regulate insect populations by laying eggs in insect larvae. It is preferable to separate the compartments of the hotel because many species do not like to live close to each other.
- Birdhouses that can regulate insect populations.
Finally, to avoid the inconvenience of certain species when you garden, try to observe the individuals that are present in your garden and adapt your schedule to their life cycle.


Last change : 03/04/22