Dynamics of lead (Pb) in different soil conditions.

ABSTRACT

Four soil samples were collected from various locations having wider range of pH and EC for incubation experiment. These soil samples were added with Pb (NO3)2 salts, and samples were taken on 1st, 35th, 45thand 60th day. Soils samples were fractioned by sequential extraction to estimate the concentration of lead in different fractions viz, water soluble, exchangeable +adsorbed, organic, carbonate and residual fraction. The result reveals that concentration of organic and carbonate bound-Pb was high in waterlogged condition and soil pH has been comprehensively identified as the single most important soil factor controlling the availability of lead (Pb) in soil. Low content of Pb in exchangeable + adsorbed (KNO3) and water soluble (H2O) fraction in all soils (except in S1) could signify low availability of Pb to plants. Bioavailable fractions, viz. water soluble and exchangeable + adsorbed, were low in all soils (except S1) well below critical limits, which may not pose any toxicity in the food chain.