Agronomic and economic evaluation of Vetiver grass (Vetiveria zizanioides L.) as means for phytoremediation of diesel polluted soils in Israel

Soil pollution in Israel, due to diesel contamination, is a major concern, with gas stations, factories and refineries being the main polluters (>60%). Vetiver grass (Vetiveria zizanioides L.) is a perennial grass belonging to the Poaceae family, and is recognized world-wide for its potential as a plant with phytoremediation traits to contaminated soils. It is demonstrated here to decrease diesel contamination in field and court-yard trials. Chemical soil analysis indicated up to a 79% decrease (P < .05) in diesel pollution of contaminated soil planted with Vetiver; and at high soil contamination levels of 10 L/m2, a significant (P < .05) reduction of 96, 96 and 87% was recorded at soil depths of 0-20, 20-40 and 40-60 cm, respectively. Furthermore, in field plots contaminated with diesel and planted with Vetiver, weeds' biomass recovered to non-polluted levels following 8 to 9 months of Vetiver treatment. An economic evaluation conducted based on the cost-benefit analysis (CBA) principles, utilizing the Net Present Value (NPV) compared phytoremediation to other currently used decontamination procedures. The economic comparison showed that phytoremediation cleanup costs are lower and more beneficial to society at large, primarily from an ecosystem services perspective. Combining the results of the agronomic examination with the economic valuation, this research pointed out that phytoremediation with Vetiver has a non-negligible potential, making it a good solution for cleansing diesel from soils on a state-wide scale in Israel and worthy of further research and development.