Evaluation of Inorganic Fractions of Arsenic in Relation to Soil Properties in Affected Areas of West Bengal, India

Inorganic soil arsenic (As) in three soils was fractionated adopting phosphorus fractionation schemes. Among these fractions, iron-bound arsenic (Fe-As) was found highest, followed by aluminium-bound arsenic (Al-As). The freely exchangeable arsenic was relatively small compared to the arsenic held by internal surfaces of soil aggregates. The arsenic fractions exhibited positive correlation with phosphorus content presumably due to the fact that high P in soil releases more arsenic from soil adsorption sites owing to the competition for the same adsorption sites. Predominantly, negative correlation of arsenic with organic carbon confirms the fact of lowering of arsenic mobility in presence of organics in soil.