Last updated on October 21st, 2023 at 10:26 pm
Composting vegetable and household waste allows it to be recycled while providing nutrients and improving the structure of the soil. But is it better to bury or spread the compost on the surface? This is a question that deserves to be addressed.
Composting household or plant waste, if done properly, produces a beautiful, fertile and aerated black humus that will serve as a natural and free fertilizer for your plants, both in the garden and in pots.
It improves the soil and encourages the life of micro-organisms and earthworms present in the growing medium, but also brings in new ones and multiplies the population already present. In poor soil, it brings nutrients and structures the soil; in heavy soil, it allows the agglomeration of fine particles, lightens the soil and makes it more permeable. We often say to mix sand with clay soil but we forget to add that without compost, the mixture will not be very effective.
Should I bury or spread the compost?
In gardening guides, it is often recommended to bury the compost in the soil. This term implies covering it with a good layer of soil, which is not necessarily as beneficial as one might think.
Indeed, from a certain depth the fauna and micro-organisms are much less numerous and active, oxygen is much rarer and yet it is it that allows the transformation of organic matter into humus through bacteria and fungi.
Based on these observations, it is much more logical to spread the compost directly on the soil and simply scratch it with a hook to make it penetrate the first few centimeters on the surface. The pedofauna will then be able to do its meticulous work in the presence of oxygen, for maximum efficiency.
How to spread your compost?
Manually weed the soil and then scratch it with a hook to make it more receptive to the nutrients and various living elements in the compost.
Spread a layer of at least 5 cm of mature compost at the foot of your plants.
Mulch with dead leaves, grass clippings or RCW to preserve soil moisture, limit the development of undesirable weeds and form a protective layer for the soil fauna.
There is a way to add even more nutrients to the soil and conserve the carbon burned in the composting process. It consists in spreading the unprocessed organic matter directly at the foot of the plants and then covering it with a classic mulch. This way, the compounds that are easiest for sowbugs, colembola, earthworms and micro-organisms to consume will be available to them and the carbon will be consumed on the spot by the soil fauna that will transform it in the best conditions.