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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 11, No. 7, 2014, pp. 1959-1972
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Bioline Code: st14192
Full paper language: English
Document type: Research Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 11, No. 7, 2014, pp. 1959-1972
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Heavy metals concentration in soils under rainfed agro-ecosystems and their relationship with soil properties and management practices
Srinivasarao, Ch.; Rama Gayatri, S.; Venkateswarlu, B.; Jakkula, V.S.; Wani, S.P.; Kundu, S.; Sahrawat, K.L.; Rajasekhara Rao, B.K.; Marimuthu, S. & Gopala Krishna, G.
Abstract
Heavy metals are governed by parent material
of soils and influenced by the soil physicochemical properties
and soil and crop management practices. This paper
evaluates total heavy metal concentrations in rainfed soils
under diverse management practices of tropical India.
Vertisols (clayey soils with high shrink/swell capacity) had
the highest concentrations of heavy metals. However,
chromium (Cr) content was above the threshold value in
Aridisol [calcium carbonate (CaCO3)]-containing soils of
the arid environments with subsurface horizon development.
Concentration increased at lower depths (>30 cm).
Basaltic soils showed higher concentrations of nickel (Ni),
copper (Cu) and manganese (Mn). Cadmium (Cd), cobalt
(Co), Cu and Mn concentrations were higher in soils cultivated
to cotton, whereas Cr concentration was above the
threshold level of 110 mg kg-1 in food crop cultivated
soils. As the specific soil surface is closely related to clay
content and clay type, soil’s ability to retain heavy metals
is more closely tied to the specific surface than to the soil
cation exchange capacity. Higher positive correlations
were found between heavy metal concentrations and clay
content [Cd(r = 0.85; p ≤ 0.01); Co (r = 0.88; p ≤ 0.05);
Ni (r = 0.87; p ≤ 0.01); Co (r = 0.81; p ≤ 0.05); Zn
(r = 0.49; p ≤ 0.01); Cr (r = 0.80; p ≤ 0.05); Mn
(r = 0.79; p ≤ 0.01)]. The amounts of nitrogen–phosphorus–
potassium applied showed a positive correlation with
Co and Ni (r = 0.62; p ≤ 0.05). As several soils used for
growing food crops are high in Ni, Cr and Mn, the flow of
these metals in soil–plant–livestock/human chain needs
further attention.
Keywords
Fertilization practices; Parent material; Tropical climate; Vertisols; Inceptisols; Alfisols; Aridisols
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