Investigating the possibility of peat substitution in olive nurseries with green compost

Peat is extensively used in olive nurseries as a primary component in commercial soilless potting media. The increased use of peat as an organic amendment with superior water holding capacity is challenged by economic and environmental pressures. To stay competitive and satisfy environmental concerns, potential alternatives to peat need to be investigated. In the present investigation, commercially available peat-based soilless mixes were amended with 25%, 50%, 75% or 100% organic green compost generated from biosolids. Results suggest that compost can be a viable partial alternative to peat as a substrate forcontainerized olive nursery production. Media amended with 25 and 50% compost provided plants with a better growth and appearance compared to unamended media. On the other hand, a higher compost content (75 or 100%), even though not affecting plant growth, improved plant susceptibility to water shortage. Green compost did not also improve heavy metal content in plant tissues. Concluding, peat-based media partially amended with green compost may have positive agronomic and economic consequences for commercial olive nursery production.