Remediation of Lead Toxicity Using Phosphorus in Lead‐Contaminated Agricultural Soils

Abstract

AbstractPhosphorus (P) plays dual role in providing plant nutrition while suppressing lead (Pb) toxicity in soil–plant system. Remediation of lead toxicity with soluble P is a promising low‐cost soil rehabilitation technology. An incubation experiment is conducted for assessing the bioavailability of Pb and P under simultaneous application in Pb‐laden soils. The treatments consist of four Pb levels, 0, 5, 10 and 20 mg kg−1 soil, and four P levels, 0, 10, 20 and 30 mg kg−1 soil, with five periods of incubation (0, 7, 15, 30 and 60 days) arranged in a 4 × 4 × 5 factorial design. The important physical, physicochemical and chemical characteristics of soil samples are analyzed. Bioavailable P and Pb contents of the soil samples after incubation with Pb and/or P are determined. The results indicate that Pb×P interactions significantly decrease bioavailable soil‐Pb concentrations by 38.9–43.9%. Likewise, interactions of Pb×day and P×day significantly reduce soil‐Pb concentrations by 33.1–35.1 and 31.8–33.6% at different levels of Pb and P spiking, respectively. A ready reckoner is developed using the antagonism manifestation of Pb and P in soil, which suggests the administration of P doses with respect to Pb‐loading and time elapsed to rejuvenate Pb‐contaminated soils for healthy crop production.