Sari University of Agricultural Sciences and Natural Resources
Abstract: (36 Views)
Background and Objectives: Nitrogen deficiency is a major limiting factor for plant growth. Although the use of urea fertilizer can compensate for this deficiency, its excessive application often results in nitrate leaching and contamination of surface and groundwater resources. Accordingly, this study aimed to evaluate the effectiveness of metal-modified biochars in reducing nitrate leaching from urea fertilizer in soils with different textures, providing a sustainable approach for environmental protection and improved soil management.
Materials and Methods: Biochar was produced from rice straw through pyrolysis at 350 °C and subsequently coated with iron, zinc, and copper. In addition, carbon–metal composites were synthesized by directly combining rice straw with these metals followed by pyrolysis. The performance of these amendments in reducing nitrate leaching was tested in three soil types—sandy clay loam, clay loam, and clay—under continuous irrigation with urea application. Nitrate concentrations in the leachates were determined spectrophotometrically.
Findings: Results indicated that soil texture had no significant effect on nitrate leaching, whereas metal modification of biochar exerted a pronounced impact. Among the treatments, copper-coated biochar showed the highest efficiency, reducing nitrate concentration to 21.79 mg L⁻¹ compared to 187 mg L⁻¹ in the control. Spectroscopic analyses confirmed the structural modifications induced by metal coatings.
Conclusion: The findings highlight that metal-modified biochars, particularly copper-coated biochar, can serve as effective tools to reduce nitrate leaching and prevent groundwater contamination. This technology offers strong potential as a key strategy for sustainable agriculture and for preserving soil and environmental health
Type of Study:
Research |
Subject:
Biogeochemistry of contaminants in soil-plant system Received: 2025/07/3 | Accepted: 2025/09/30