PROJECT DESCRIPTION
BACKGROUND
The use of peat moss in horticulture has contributed to a 70% loss of European peatland areas over the past 25 years. Peat moss is the most common material used to grow potted plants and trees. Despite recent EU directives to protect wetlands, increased demand from the horticultural sector is destroying these natural habitats. More sustainable substitutes such as tree bark, wood fibre, composted sludge and green waste have been tested, but producers consider them to be less effective. Recent changes in EU legislation regarding the management of sediment from seas and rivers could offer a new alternative. EU legislation allows for sediment dredged from ports to be reused commercially, provided that it poses no risk to human health or the environment.
OBJECTIVES
LIFE SUBSED seeked to show that dredged sediments can be converted into an economically viable and environmentally sustainable alternative to peat moss for use in horticulture. The project aimed to use an innovative sediment-based growing medium in plant nurseries to cultivate food crops, such as olive, citrus, basil and blueberry, and ornamental plants including laurel. The project intended to favour efficient and cost-effective techniques to increase profits and gain support from professionals and policymakers. Technical training sessions and communication tools would also help transfer and replicate project results throughout Europe.
By making better use of natural resources, the project would be in line with the requirements of the EU Waste Framework Directive and the circular economy package. It aimed also to reduce the impact of the horticultural sector EU peatlands protected under the Habitats Directive and the EU biodiversity strategy. The aim of reducing carbon dioxide emissions from the plant growth medium is in line with the 2020 climate and energy package.
RESULTS
The LIFE SUBSED project demonstrated the feasibility of converting dredged marine sediment (waste) into an economically viable and environmentally sustainable alternative to peat moss for use in horticulture. The dredged sediment was remediated through a land farming approach that was demonstrated in a previous LIFE project and then mixed, in different proportions, with peat and other materials that are typically used to produce plant-growth substrates. The project team then tested these substrates in Italy and Spain in the nursery production of ornamental plants and the cultivation of food crops, the nutritional quality of which was also evaluated.
At its end, the project showed that the use of peat in the growing media could be reduced by 39%, yielding an overall reduction of CO2 emissions associated with the long-distance transportation of peat. The project also confirmed that substrates composed of up to 50% in mass of dredged sediment are suitable for plant growing in nurseries. The project’s methodology represents a promising new business opportunity. A specific end-of-waste procedure for marine dredged sediment has been successfully tested and it is in line with the Italian regulatory framework on waste and fertilisers.Technical guidelines were produced for public administrations and professionals. Training sessions have been also carried out.
Further information on the project can be found in the project's layman report (see "Read more" section).
