Phytoextractability of lead from soil by some oilseed crops as affected by sewage sludge and farmyard manure

Abstract

Screenhouse experiments were conducted to study the phytoextractability of lead (Pb) by three oilseed crops (Brassica juncea, Brassica napus and Eruca sativa) from Pb enriched (i.e. 0, 200, 400, 600 and 800 mg Pb kg⁻¹ soil) unamended, sewage sludge-amended (SS-amended) and farmyard manure-amended (FYM-amended) sandy loam soil. Chlorotic symptoms and stunted growth were observed at Pb₆₀₀ and Pb₈₀₀ treatments. Sewage sludge and FYM slightly decreased chlorosis. The biomass production for amendment treatments followed the order: FYM-amended > SS-amended > Unamended soil, and for species: Brassica juncea > Brassica napus > Eruca sativa. The Pb concentration followed the order: leaf > stem > seed, Brassica napus > Brassica juncea > Eruca sativa, and SS-amended > Unamended > FYM-amended soils. The Pb uptake followed the order: Brassica juncea > Brassica napus > Eruca sativa, and SS-amended > Unamended > FYM-amended soils. Exchangeable and Fe-Mn oxide bound fractions decreased and organic matter bound fraction increased with sewage sludge and FYM. The carbonate bound fraction considerably decreased with FYM.

Keywords:

• Brassica
• farmyard manure
• lead
• phytoextraction
• sewage sludge

Acknowledgements

The first author (AKI) expresses deep sense of gratitude to Dr R. S. Siyag for arranging research facilities and other help during the course of this investigation.