Phytostabilization of Chromium by Organic Amendments in Sunflower (Helianthus annus L.) Field Soil

Chromium, in the trivalent form (Cr III), is an important component of a balanced human and animal diet and its deficiency causes disturbance to the glucose and lipids metabolism in them. But the concentration above the permissible limit causes the crop failure and human health impacts. In contrast, hexavalent Cr (Cr VI) is highly toxic, carcinogen and may cause death in animals and humans if ingested in large doses. Recently, concern about Cr as an environmental pollutant has been escalating due to its buildup to toxic levels in the environment as a result of various industrial and agricultural activities. In our study, a reduction of chromium of about 87 per cent was recorded in sunflower field. At the same time reduction of only 33.8 per cent from the initial concentration of Cr in the surface soils under sunflower was observed due to the addition of organic amendments. Such reduction is attributed to the formation of either organo-chromic complexes (Immobilization) or chelates. Phytostabilization utilizes the plant production of compounds, which immobilize contaminants at the interface of ischolar_mains and soil, or ischolar_main and water. An example of this method is where ischolar_main exudates cause the precipitation of metals, reducing their bioavailability.