FRETILISERS IN INDIAN AGRICULTURAL SYSTEM (II ): ADVERSE IMPACTS ON SOIL, ENVIRONMENT, AND HUMAN HEALTH

Abstract

Long-term fertilizer experiments (LTFE) of India, which received regularly fertilizers for many decades serve as the ideal sites for monitoring buildup of the heavy metals added through them. Soil and plant samples were monitored for the accumulation of these metals. Results presented in Figure 6 did not show any specific pattern/trends of heavy metal accumulation/status in the soils after 35 years of continuous application of fertilizers under different treatment combinations. In general, accumulation of chromium (Cr) and cadmium (Cd) was much higher than lead (Pb), nickel (Ni) and cobalt (Co) (Figure 6). Use of phosphatic fertilizers like, DAP and SSP and organic manures have been identified as the major products responsible for increase in the heavy metal contents in the soil. Phosphate rock used as raw material in manufacture of phosphatic fertilizers contain lot of impurities in the form of heavy metals. At Ludhiana, Cr was recorded in the FYM-amended plot. Since FYM is an output of animal dung which is fed on fodder probably grown on soil contaminated with Cr, this could be the route of its entry into the soil. Currently, the contents of heavy metals at all the LTFE centers are far below the safe limits reported in literature