Skip to main content

Abdelaziz Ouidad

  • Biodiversity Journal, 14 (1): 0217-0221

    Zekri Jihane, Merradi Manel, Abdelaziz Ouidad & Maalem Nour el Houda
    Assessment of metal and mineral contents in soils amended by sludge in cork oak seedlings
    https://doi.org/10.31396/Biodiv.Jour.2023.14.1.217.221

    ABSTRACT
    The cork oak (Quercus suber L.) is a tree species that has a high economic and naturalistic value. It was chosen for this job since we explore the possibility to improve the choice of sludge-based growing media in order to enhance the nutrition quality for plants by minerals and trace elements and to assess the level of contamination by heavy metals (lead, copper, etc.). The biometric parameters of the meristem growth, aerial and underground biomass are the main criteria for the standardization of plants. Seven types of substrates were tested for raising seedlings. The dosing of heavy metals was carried out on the various substrates before sowing and after 18 months. The results showed morphogenetic differences for the seven substrates, particularly for the pine bark and olive pomace mix sludge and also high levels of nitrogen, phosphor, potash (NPK) and heavy metals mainly for substrates amended by sludge. The high levels of heavy metals induce high soil pollution that may be used as bio-indicator of toxicity, reflecting the sensitivity of the species. The obtained results showed high levels of NPK for four substrates, but according to the standards these levels do not exhibit harmful effects on the growth. The plants cultured with sludge-based substrates, namely substrates S1 and S2 (<25% sludge), showed levels of heavy metals according with the standard Osol (1986). These substrates can be recommended, however; substrates S3 (45% sludge) and S4 (65% sludge) have high levels especially of lead and copper thereby affecting the growth parameters. Therefore, these latter are unfavorable substrates for growth and the species is sensitive for their high concentrations in the sludge. Finally sewage sludge have qualities and ideal characteristics for a recovery in forest areas but requires a good study for the future of these heavy metals in plant tissues and in the ecosystem.