Investigation on the potential of eco-friendly bio-char for amendment in serpentine soils and immobilization of heavy metals contaminants: a review

Serpentine soils are contaminants of naturally occurring metal-rich agricultural and fallow lands due to erosion of the serpentine site with consequences and deterioration of soil, water quality, and water sources in the ecosystem. The harsh climatic conditions due to the high concentration of potential toxic elements, organic pollutants, and acidity make it difficult to cultivate and establish vegetation on serpentine or adjacent land. Recently, biochar amendments have emerged in the area of soil remediation technology with the suitability and potential to promote seed emergence, plant growth, biomass productivity, and vegetation cover on contaminated soils such as serpentine soil. By enhancing the buffering capacity of the soil through pH, soil nutrients and water holding capacity stimulate the diversity and function of microbes. In this review, we have conferred the physicochemical aspects of serpentine soil, heavy metal contaminants, and their consequences, especially in crop production and phytotoxicity. Another, the assessment of biochar preparation using various types of feedstock, their characteristics, and the application for the amendment of serpentine soils has been deliberated. The restoration of sites with a high fraction of heavy metal contaminents and organic pollutants associated with serpentine soils using biochar has been highlighted for its importance. In line with the possibility of expanding the cultivated area, future research directions have been suggested in field trials, advances in biochar production, and environmental risk assessment. In addition, the applicable mechanisms have prerequisites to accelerate the efficiency of biochar amendments.