International Journal of Chemical Studies
Vol. 5, Issue 3 (2017)
Distribution of Geochemical fractions of Zn, Fe, Cu and Mn under different landuses of Temperate Himalayas
Author(s): Shazia Ramzan and M Auyoub Bhat
Abstract: Research interests have moved from total element composition of the soil sample towards speciation analysis to separate and to identify specific or binding forms of metals and allows assessing the availability and mobility of metals in order to understand their chemical behavior. Soils were collected from the five agricultural landuses (cereals, apple orchards, vegetables, saffron, pastures and forests) of Temperate Himalayas. A sequential extraction procedure was used to fractionate heavy metals in six geochemical fractions i.e., water-soluble, exchangeable, carbonate bound, iron and manganese oxide bound, organic bound and residual fractions. Results indicated that the chemical partitioning trend and per cent distribution in each geochemical fraction varied under each land use system due to varied soil properties and agricultural practices. Water soluble, exchangeable and organic bound fractions of heavy metals were highest in pasture and forest soils while as carbonate bound fraction was maximum in saffron soils. In the five land uses studied, the average potential mobility of Zn, Fe and Mn was highest in forest and pasture soils while as Cu mobility was found highest in cereal soils. The results suggest that there is no serious contamination hazard with the Zn, Fe, and Mn studied, considering the geochemical phases in which they were associated but the Cu with relatively high mobility factors coupled with its comparatively high concentration in the exchangeable fraction in cereal soils indicates high mobility, liability and bioavailability for cereals and may pose a threat of toxicity in cereal crops. Influence of soil properties on different fractions of heavy metals was evaluated by simple correlation and multiple regression analysis. Multiple regression indicated that pH and organic carbon of soils correlate greatly with available (water soluble and exchangeable) and organic bound fractions. Calcium carbonate content correlated significantly with carbonate fraction of Zn and Cu while as CEC contributed greatly to water soluble Mn. The results of this study indicated that the sequential extraction procedure, in conjunction with multiple regression analysis, may be useful for understanding the influence of landuses on the distribution of heavy metals in soils and the soil properties that greatly influence the different fractions.
Pages: 734-744 | 688 Views 18 Downloads
How to cite this article:
Shazia Ramzan, M Auyoub Bhat. Distribution of Geochemical fractions of Zn, Fe, Cu and Mn under different landuses of Temperate Himalayas. Int J Chem Stud 2017;5(3):734-744.