ORGANO-MINERAL FERTILIZER (OMF) AS SUPPLEMENT FOR SUNFLOWER (HELIANTHUS ANNUUS) ACTUATED PHYTOREMEDIATION

Abstract

Heavy metal contamination of soil, particularly by cadmium (Cd), poses serious environmental and public health risks due to its persistence, toxicity, and ability to enter the food chain. This study evaluated the effectiveness of organo-mineral fertilizer (OMF) in enhancing sunflower (Helianthus annuus)-mediated phytoremediation of cadmium-contaminated soil. A field experiment was conducted using a randomized design comprising OMF-treated and control plots. Soil samples were collected before planting and after harvesting, while plant samples were analyzed for cadmium distribution in roots, shoots, leaves, and seeds. Cadmium concentrations were determined using atomic absorption spectrophotometry, and plant biomass (fresh and dry weights) was also measured. The results showed a significant reduction in soil cadmium levels, with OMF-treated topsoil exhibiting a higher percentage removal compared to control plots. Cadmium accumulation in sunflower followed the trend: root > shoot > leaf > seed, indicating that the plant effectively sequesters metals in its vegetative parts. OMF treatment enhanced cadmium uptake and translocation within the plant, resulting in higher concentrations in roots, shoots, and leaves. However, cadmium levels in seeds were lower in OMF-treated plants, suggesting reduced transfer to edible parts. Additionally, OMF significantly improved plant growth, as evidenced by increased fresh and dry biomass across all plant parts. These findings are consistent with previous studies that reported improved phytoremediation efficiency with soil amendments. In conclusion, sunflower combined with organo-mineral fertilizer is an effective and sustainable approach for the remediation of cadmium-contaminated soils. It is recommended that this method be adopted for large-scale remediation, with further research focusing on long-term impacts and optimization under varying environmental conditions.