Scenario of heavy metal contamination in agricultural soil and its management

Abstract

Soil is a complex structure and contains mainly five major components i.e. mineral matter, water, air, organic matter and living organisms. The quantity of these components in the soil does not remain the same but varies with the locality. Soil possesses not only a nucleus position for existence of living being but also ensures their future existence. Therefore, it is essential to make an adequate land management to maintain the quality of soil in both rural and urban soil. The presence of different kinds of heavy metals such as Cd, Cu, Mn, Bi and Zn etc. in trace or in minimum level is a natural phenomenon but their enhanced level is an indicator of the degree of pollution load in that specific area. The precise knowledge of these kinds of heavy metals, their forms and their dependence on soil provides a genuine base for soil management. The heavy metals have potent cumulative properties and toxicity due to which they have a potential hazardous effect not only on crop plants but also on human health. The metal contaminants can be reduced by immobilization of contaminants using macrophytes and also by using genetically engineered microorganisms.

Pearl millet (Pennisetum Glaucum L.) response after ferti-irrigation with sugar mill effluent in two seasons

“…Organic matter supplied through the sugar mill effluent and other kind of wastes, like sludge, can lower the BD and WHC (Roy et al 2007). The findings were also in accordance to Baskaran et al (2009) (Chopra et al 2009). …”

“…Thus, contamination of agricultural soils with metals can pose long-term environmental problems, and is not without health implications (Ferguson 1990;Chopra et al 2009). The amounts of metals mobilized in the soil environment is a function of pH, clay content, organic matter, cation exchange capacity, and other soil properties making each soil unique in terms of pollution management (Baruah et al 1993;Kumar and Chopra 2012).…”

“…Irrigation with effluents increases accumulation of metals in soil, and increases chances of their entrance in food chain (Chopra et al 2009). Thus, contamination of agricultural soils with metals can pose long-term environmental problems, and is not without health implications (Ferguson 1990;Chopra et al 2009).…”

“…The amounts of metals mobilized in the soil environment is a function of pH, clay content, organic matter, cation exchange capacity, and other soil properties making each soil unique in terms of pollution management (Baruah et al 1993;Kumar and Chopra 2012). The metals Cu, Fe, Ni, Zn, and other trace elements are important for proper functioning of biological systems, and their deficiency, or excess, could lead to a number of disorders (Chopra et al 2009). Metals are capable of forming insoluble complex compounds with soil organic matter, and contents of Cd, Cu, Ni, Mn, and Zn are dependent on the pH of soil solution and soil organic matter (Kim and Kim 1999).…”

Phytoremediation of Heavy Metals from Paper Mill Effluent Soil Using <i>Croton sparsiflorus</i>

“…Irrigation with effluents is known to contribute significantly to the heavy metals content of soil as well as crop plants [3][4][5]. Heavy metals are very harmful because of their non-biodegrable nature, long biological half-lives and their potential to accumulate in different body parts [6][7][8]. Most of the heavy metals are extremely toxic because of their solubility in water [3,9,10].…”