TITLE:
Levels of Heavy Metals in the Soil: Effects of Season, Agronomic Practice and Soil Geology
AUTHORS:
Monsurat Temitope Osobamiro, Gregrory Olufemi Adewuyi
KEYWORDS:
Heavy Metal, Farm-Settlement, Agro-Ecosystem, Seasonal Variation, Soil Mineral
JOURNAL NAME:
Journal of Agricultural Chemistry and Environment,
Vol.4 No.4,
November
26,
2015
ABSTRACT: Heavy metals status of agricultural soils should be monitored in order to prevent soil-plant pollution. This study evaluates the effect of season, agronomic practice and soil mineral composition on the levels of some heavy metals (Pb, Mn, Ni, Fe, and Zn) in the arable and oil palm soils of three Farm Settlements in Ogun-State Southwest, Nigeria. Soil samples were collected in two consecutive seasons between 2010 and 2012 and digestion was carried out using Standard Wet Acid Digestion method. Total heavy metals in the digest were determined using Flame Atomic Absorption Spectrophotometer (FAAS). The total levels of heavy metals (in mg/kg) found in the sampled soils were as follows: in the rainy season Mn (28.4 - 34.2), Fe (1599.7 - 2013.2), Pb (11.0 - 16.9), Zn (100.5 - 112.9) and Ni (11.3 - 13.8) and in the dry season Mn (32.1 - 40.1), Fe (1701.4 - 2455.5), Pb (13.0 - 18.7), Zn (105.7 - 110.4) and Ni (15.5 - 16.3). Levels of the heavy metals found in the sampled soils were significantly lower (p