Effect of inorganic anions on yield and micronutrient content of Indian rape (Brassicae campestris var. toria) in lead spiked soil

A greenhouse pot experiment was conducted to study the influence of different inorganic anions on seed yield and micronutrient content of seeds of Indian rape in a lead (Pb) spiked soil. Soil was artificially contaminated with four levels of Pb (0, 50, 100, 200 mg kg⁻¹ soil) and amended with potassium salts of four anions viz. H₂PO₄⁻, Cl⁻, SO₄^2-, CO₃^2-at 0, 60, 120 and 240 mg kg⁻¹ soil. Seed yield of Indian rape decreased significantly with increased Pb spiking in soil. The highest mean seed yield was recorded where the soil was amended with H₂PO₄⁻ followed by CO₃^2-and SO₄^2-but addition of Cl⁻reduced the seed yield. The Pb content of seeds enhanced significantly and sequentially with increasing rates of Pb contamination of soil. The micronutrient (Fe, Cu, Mn and Zn) content of seeds of Indian rape decreased markedly and significantly with increasing Pb levels. However, application of H₂PO₄⁻ and CO₃^2-to soil significantly increased the micronutrient content but application of Cl⁻resulted in a decrease in micronutrient content. The results of the experiment demonstrated that addition of H₂PO₄⁻ and CO₃^2-anions lowered the bioavailability of Pb and increased the micronutrient composition of crops grown on Pb contaminated soil, indicating their potential for in situ remediation in Pbcontaminated soils.