Mobility of lead and nickel in soil in relation to nutrition of sesame

Abstract

The availability of lead and nickel in soil is greatly influenced by farmyard manure. We conducted two pot culture experiments in an Aeric Haplaquept to study the mobility of lead and nickel in soil and their uptake by sesame (Sesamum indicum L.) plant as influenced by the application of farmyard manure. Application of lead (0–500 mg kg−1) and nickel (0–500 mg kg−1) at different doses to soil and plant increased their availability and such increase was counteracted by the application of farmyard manure (0–3% by weight of soil). The lead and nickel concentrations in soil and shoot dry matter of sesame gradually decreased with the progress of crop growth. The highest DTPA-extractable Pb and Ni was 119.3 and 215.5 mg kg−1 in the treatment Pb500 and Ni500, respectively, at 15 days of incubation. The highest Pb and Ni concentrations in the shoot of sesame plant were 23.8 and 24 mg kg−1observed in the treatment Pb500 and Ni500, respectively, at 15 days of crop growth. The toxic limit of applied Pb and Ni concentration to soil for shoot growth of sesame plant was 50 and 100 mg kg−1, respectively.