Investigation of the effects of agricultural activities on the accumulation of cadmium, cobalt and chromium in soil

Every year a great deal of chemical fertilizers, pesticides and sewage sludge used in agriculture soils; this may cause the increase in concentration of Soil heavy metals. The purpose of this study was to investigate the effects of assessment of agriculture activities on accumulation of Cadmium, Cobalt and Chromium; and determines the trend of heavy metal accumulation in soil.

To achieve this purpose 97 soil samples were taken from different agriculture fields with different cultivation archaism in Hamedan province in western IRAN by systematic approach. ANOVA test has been used to compare the concentration of heavy metals in different farms, the trend of accumulation heavy metals obtained in regards to cultivation archaism and the mean of metals concentration in different cultivations. Moreover, contamination Factor Index has been used for comparison of contamination risk in cultivations with various archaisms.

Mean concentrations in 20-, 35- and 65-year-old cultures for cadmium metal were 0.14, 0.16 and 0.19, respectively, for cobalt metal, 17/94, 18/05 and 79/20, respectively and for chromium metal 58.89, 72.99 and 88.09 mg / kg, respectively. The results showed that the longevity of cultivation affected on heavy metal accumulation in soil. The trend of Cd, Co and Cr accumulation in soil was exponential.

Due to the fact that agricultural soils are one of the important routes for the transfer of heavy metals to the human food chain, it is necessary to monitor soils that are potentially exposed to toxic metals.