Journal of Climate Change and Pollution

ABSTRACT

Soil contamination by petroleum hydrocarbons and heavy metals threatens agricultural productivity and public health in semi-arid regions like Nigeria's Sudan Savannah. Phytoremediation using  Jatropha curcas offers a sustainable strategy, yet the influence of propagation method on remediation efficiency remains underexplored. A 12-week pot experiment was conducted at Aliko Dangote University of Science and Technology, Wudil, using a Completely Randomized Design with three replications. The study evaluated phytoremediation potential of  Jatropha curcas propagated by seed (JS) and stem cuttings (JC) in soils contaminated with two petroleum levels (1000 mL and 1500 mL per 12 kg soil). Unplanted contaminated controls were included. Total Petroleum Hydrocarbons (TPH) were analyzed using Gas Chromatography-Flame Ionization Detector, heavy metals (Pb, Cd, Zn, Cu) using Atomic Absorption Spectrophotometry, and soil physicochemical properties were assessed following standard protocols. Data were analyzed using ANOVA with means separated by Tukey's HSD test (p < 0.05).  Jatropha curcas significantly reduced TPH compared to unplanted controls. Seed-propagated  Jatropha achieved the lowest residual TPH (24,530.5 mg/kg at 1000 mL; 36,683.9 mg/kg at 1500 mL) and highest remediation efficiencies (62.4% and 62.7%), outperforming cutting-propagated plants (56.4% and 59.3%). Soil physicochemical properties improved significantly under vegetation, with JS-treated soils showing highest pH (7.11), organic carbon (1.88%), cation exchange capacity (5.80 cmol/kg), and available phosphorus (18.8 mg/kg), alongside reduced bulk density (1.59 g/cm³) compared to contaminated controls.  Jatropha curcas demonstrates strong phytoremediation potential for petroleum-contaminated soils in the Sudan Savannah, with seed propagation proving superior to stem cuttings due to enhanced root development. The plant's ability to simultaneously restore soil fertility supports its dual role in environmental cleanup and land rehabilitation.

Keywords: Phytoremediation;  Jatropha curcas; Petroleum Hydrocarbons; Heavy Metals; Sudan Savannah; Propagation Methods; Soil Restoration