Compost is an amendment that derives from the bio-oxidation and humification of a mixture of organic materials (for example pruning residues, kitchen waste, manure) by macro and micro-organisms. In order for this to happen, certain specific conditions have to be met: the presence of oxygen and equilibrium between the chemical elements of the matter undergoing transformation. Composting, or biostabilisation, is an aerobic biological process that is controlled by man and leads to the production of a mixture of humified substances (the compost) starting from biodegradable residues through the action of bacteria and funguses. It can be used to improve the soil to then be used for agronomic or gardening nursery purposes. By contributing organic substances, using it improves the soil structure and availability of nutritious elements (composts of phosphorus and nitrogen). As a biological activator, it also increases the biodiversity of the microflora.