Compost in floriculture

Compost or earthworm casts from different organic wastes, including farmyard manure, urban and agricultural wastes, were used as alternative substrates in floriculture to ascertain the possibility of using them both in plant propagation and as growth media. The use of composts in addition or in substitution for organic or inorganic components of potting media has often been suggested since these materials provide plants with a sufficient share of nutrients, have an adequate organic base and a satisfactory water-holding capacity. Experiments on plant propagation performed both on layers and shoots of several ornamental plants showed that, although in a different extent, composted materials favour rooting, rooting initiation and root biomass development. These effects are particularly enhanced by earthworm casts. Results concerning the use of both composts as growth media showed that lower amounts of chemical fertilizers were required to reach production and quality comparable with the control.