Compost-assisted phytoremediation

Abstract For centuries, organic wastes have been used in agricultural operations as soil amendments. Various organic amendments are frequently utilized in agricultural operations because they have been known to improve soil health properties like water holding capacity, nutrient availability, porosity, etc., and biological properties like microbial activity. Compost, when added to the soil as an amendment, has an immediate impact on various physicochemical properties like pH, OC, metal (loid) solubility, etc. Organic waste amendments, when applied to heavy metal contaminated soils not only enhance its fertility properties but also diminish bioavailability and mobility of potentially toxic elements by promoting certain processes like complexation, sorption, etc. The application of these amendments ameliorates the phytoremediation process in contaminated sites. Amendment of soil with compost enhances the growth of plants as well as favors the activity of soil microbiota. These two associates together to strengthen the process of phytoremediation, plant resilience towards stress as well increase the production of plant biomass. It has also been suggested that compost application instigates differential impact on the plants according to their species. The utilization of compost as an organic amendment in various agricultural practices has been reported to enhance soil fertility, crop production, as well as assist in phytoremediation of metal-contaminated sites. However, there is a need to evaluate each organic waste amendment/compost for its effect on metal mobility before its application in fields. More extensive research is needed to increase our understanding of the mechanisms involved in assisted phytoremediation compost application in contaminated sites.