Soil Biogeochemistry, Plant Physiology, and Phytoremediation of Cadmium-Contaminated Soils

TLDR: In this article, a review of recent progress in soil biogeochemistry and plant physiology of Cadmium, mechanisms of hyperaccumulation of Cd in plant, remediation strategies including chemical and microbiological enhancement, and optimization of field management practices, in the hope to stimulate more research in the future.

Abstract: Cadmium (Cd) loading in soil and the environment has been accelerated worldwide due to enhanced industrialization and intensified agricultural production, particularly in the developing countries. Soil Cd pollution, resulting from both anthropogenic and geogenic sources, has posed an increasing challenge to soil quality and food security as well as to human health. Compared with other heavy metals such as copper (Cu) and lead (Pb), Cd demonstrates greater mobility along food chain and in the environment. Cd is harmful to human health and potentially toxic to biota at lower concentrations. Therefore, it is imperative to develop management strategies for control of pollution sources and remediation of contaminated soils. Extensive studies have been conducted in recent years to understand biogeochemical processes of Cd in soils, its cycle in agroecosystems, impacts on soil quality and food security, and the remediation of Cd-contaminated soils. Phytoremediation as an emergent technology has stimulated refreshed interest since it is cost effective and ecofriendly, especially the use of metal hyperaccumulating plants to extract or mine heavy metals from contaminated soils. Progress has been made in the understanding of mechanisms that govern Cd accumulation and detoxification in accumulating plants. This review provides recent progress in soil biogeochemistry and plant physiology of Cd, mechanisms of hyperaccumulation of Cd in plant, remediation strategies including chemical and microbiological enhancement, and optimization of field management practices, in the hope to stimulate more research in the future.