P ollution of heavy metal limits the development and safety of agricultural goods produced in soil and can create remarkable ecological destruction to the environment. Cadmium is one of the greatest threatening components for human health as well as for environment. It is also a needless and nonrenewable component for plants (Zhu et al., 2020). Its existence in the soil is deliberated a thoughtful environmental problem chiefly due to its entrance in the human food chain with hazardous special effects on living entities (De Maria et al., 2013). Toxicity of Cd causes irregularities and inhibition of overall development in numerous species of plant. After extended period exposure to Cd, roots become mucilaginous, decomposing, and browning, and disintegrating; lessening of roots and shoots elongation, rolling and chlorosis of leaves can occur (Tran and Popava, 2013).Biochar is accepted as a soil amendment having Abstract | Heavy metals Pollutants are not only dangerous to human life but also to fauna and flora. The existence of cadmium (Cd) in soil, atmosphere or water may unfavorably affect growth and physiology of plants. The experiment was conducted to study the impacts of biochar on the growth and physiology of tomato grown in Cd contaminated soil and activity of biochar in the contaminated soil. In this study different treatments of Cd were applied in the presence of certain portion of biochar. The order of treatments was 0 mg Cd as control with biochar (12%), low Cd (10mg), high Cd (15mg), low cadmium + biochar (10mg+12%) and high cadmium + biochar (15mg+12%) with distilled water as control. Growth and physiological parameters of plant were studied and prominent results were observed. The results showed that biochar has significant progressive effects on the growth and physiology of tomato by limiting the uptake of Cd by plants. As the concentration of Cd increased to high i.e. 15 mg/kg of soil, the limiting capacity of biochar was also seen less effective.

IntroductionC admium is highly toxic element abundantly found in nature, and an important component of earth layer (crust) including soil, water, air, underground soil, mines, plant tissues, animal tissues, and ores. Cadmium may cause adverse effects on human, animal and plants health especially when its concentration exceeds the limit due to continuous produc-tion. Cadmium ranges in earth crust between 0.1 to 0.5 ppm, in marine Because of high environmental and human health concerns, a lot of research has been done over the past 50 years. Sources of Cd emission are both natural and anthropogenic (manmade). Total Cd emission from natural sources ranges from 10-50% (Morrow et al., 1995;Nawrot et al., 2006). Mining activities are the biggest source of Cd emission in environment and contaminate soil, air, water Abstract | Cadmium (Cd) is highly toxic metal which naturally exists in environment in small proportion but continuously increasing due to anthropogenic activities. The rapid increase in population is putting pressure on urbanization, agriculture and industrialization which have resulted in gradual increase in Cd level. It is released from industries as an impurity and pollutes soil, water and air in different ways. High solubility in water increases its mobility in the soil ecosystem. The use of sludge and chemical sprays on crops increase the Cd contamination besides some other heavy metals. Through nutrient cycling, it is taken up from the soil to plants and finally becomes the part of human body which warrants serious health concerns. Cadmium causes mild to severe effects on plants, animals and environmental health. Humans are exposed to cadmium through food, water intake, inhalation (cigarette) and dermal contact which then produces heart disease, kidney failure, lung cancer, orthopedic disease, nervous system failure, low immunity level, mental retardation and growth retardation. Different environmental friendly and low cost biological remedies are used nowadays to control Cd toxicity such as phytoremediation phytostabilisation, rhizofilteration, phytoextraction. This review paper has summarized the impact of Cd on soil, plants and humans and strategies to remove or minimize its toxicity by applying some low cost and environmental friendly techniques.