Phytoremediated marine sediments as suitable peat-free growing media for production of red robin photinia (Photinia x fraseri)

Abstract

Sediments dredged by an industrial port, slightly contaminated by heavy metals and petroleoum hydrocarbons, were phytoremediated and used as peat-free growing media for the red robin photinia (Photinia x fraseri L.). Plants were grown on sediment only (S), sediment mixed with composted pruning residues (S + PR), sediment fertilized with controlled release fertilizers (S + F) and peat-based growing media as control (C). Plant elongation and dry weight, leaf contents of chlorophyll, malondialdehyde (MDA), macronutrients and heavy metals were determined at the end of one growing season. Environmental impact related to the use of sediment-based as compared to peat-based growing media was assessed by the Life Cycle Analysis (LCA). Sediment-based growing media presented significantly higher bulk density, pH and electrical conductivity values, lower C and N contents, and significantly higher total and available P. Red robin photinia grown on S + F growing media showed morphological and chemical parameters similar to those of control plants (C), whereas plants grown on S and S + PR showed lower growth. Leaf concentration of nutrients and heavy metals varied depending on the considered element and growing media, but were all within the common values for ornamental plants, whereas the highest MDA concentrations were found in plants grown on traditional growing media. The LCA indicated the use of sediments as growing media reduced the C footprint of ornamental plant production and the contribute of growing media to the environmental impact per produced plant. We concluded that sediments phytoremediation and use in plant nursery is a practical alternative re-use option for dredged sediments.

Remediated marine sediment as growing medium for lettuce production: assessment of agronomic performance and food safety in a pilot experiment

“…The sediment used in this study contained higher amounts of heavy metals and organic compounds potentially detrimental for plants compared to the traditional peat‐based growing medium (Table ), but no phytotoxic effect of TS50 and TS100 was noted on lettuce. In fact, plants did not show any symptoms of toxicity, suggesting that, as observed in previous studies, heavy metals were not available to plants . Nevertheless, lettuce grown in TS100 showed lower head fresh weight, dry weight and leaf area in comparison with plants cultivated in TS0 and TS50, as shown also by PCA.…”

“…While the possibility of using reclaimed sediments as growing media in nursery production of ornamental shrubs and trees has been demonstrated, to our knowledge this is the first study assessing the suitability of reclaimed sediments for growing a food crop. As a first approach to this issue, lettuce was chosen among food crops, being a good indicator of the physical and chemical soil/substrate quality .…”

“…Phytoremediation leads to degradation of organic pollutants and chemical stabilization of heavy metals, improves structure and water retention and increases the microbiological activity, converting the dredged sediments into a biologically active matrix . Phytoremediated sediments have already been successfully used as growing media in ornamental and forest tree nurseries . Moreover, life cycle analysis (LCA) applied to the production process of ornamental plants in the Pistoia district (central Italy) demonstrated that replacing the conventional growing media (mainly peat) with reclaimed sediments significantly reduced the environmental impact of nursery activity …”

“…[4][5][6] Phytoremediated sediments have already been successfully used as growing media in ornamental and forest tree nurseries. [7][8][9] Moreover, life cycle analysis (LCA) applied to the production process of ornamental plants in the Pistoia district (central Italy) demonstrated that replacing the conventional growing media (mainly peat) with reclaimed sediments significantly reduced the environmental impact of nursery activity. 8 In the present study, we hypothesized that phytoremediated sediments could be used as growing media for the production of leafy vegetables.…”

“…[7][8][9] Moreover, life cycle analysis (LCA) applied to the production process of ornamental plants in the Pistoia district (central Italy) demonstrated that replacing the conventional growing media (mainly peat) with reclaimed sediments significantly reduced the environmental impact of nursery activity. 8 In the present study, we hypothesized that phytoremediated sediments could be used as growing media for the production of leafy vegetables. In order to verify this hypothesis, lettuce plants were grown in a phytoremediated sediment, used pure or mixed with peat, and crop response was evaluated for both yield and quality.…”