Traditionally the use of soil improvers in agriculture is aimed at the restoration of the organic substance removed from the agro-ecosystem by crops. The addition of humus, as replacement for the portion gradually mineralised by the micro-organisms of the soil, leads to the conservation of its fertility under many point of view: physical (e.g. porosity, drainage, aeration), chemical (availability of nutrients) and biological (intensity of the microbial activities) fertility of the soil itself. In such a respect, the amount of nutrients in a compost is seen as a positive and significant characteristic because the nutrients released during compost degradation get available for the vegetable needs. On the other end, the nitrogen concentration could be a limiting feature referring to maximum nitrogen load.
A different evaluation has to be done for other sectors such as horticulture, floriculture, fruit culture, tree nursery where compost is mainly used as growing media in potting. In this case the main feature to be assessed are properties such as total porosity, hydrophilicity, permeability, conductivity of water solutions.
Thus, it is possible to identify two different main uses of the composted products:
- as soil improvers
- as growing media
Starting from the evaluation of specific technical features for the composted materials and comparing them to the traditional fertilisers, it is possible to define marketing opportunities and technical conditions to promote the use of composted products.