Phytotoxic effects of petroleum hydrocarbons on germination and growth of the native halophyte Salicornia sinus persica in oil contaminated soil

The release of petroleum hydrocarbons (PHCs) into the environment is primarily linked to petroleum industry activities, including drilling, exploration, storage, and related processes. The spillage of PHCs into the environment poses significant threats to ecosystems and can lead to serious risks to human health, the environment, and plants. This research aims to investigate the phytotoxic effect of petroleum sludge on the germination and growth characteristics of Salicornia sinus-persica. This study was conducted in a greenhouse using pots to examine the effects of varying concentrations of PHCs on plant growth. Petroleum sludge at concentrations of 0, 0.2, 1, 2, 4, and 8% (w/w) was used to prepare PHC-contaminated soils. In some pots, biochar, and vermicompost were added to them in order to evaluate the effect of soil amendments on plants. The study evaluated several parameters, including seed germination, fresh and dry biomass weight, number of lateral stems, stem and root lengths, and chlorophyll a, b, total chlorophyll, and carotenoids. The results of this study showed that petroleum contamination had negative effects on the growth parameters of Salicornia sinus persica and photosynthetic pigments. However, the addition of biochar and vermicompost as soil amendments improved plant growth under contaminated conditions. Salicornia dried after 1 month in oil-contaminated soils with a concentration of 8% in all soil treatments, which indicated its high toxicity to the plant.