Abstract

Background: The rural-urban fringe represents a critical transition zone where agricultural lands face increasing pressure from urban expansion. This study examines the multifaceted impacts of urbanization on agricultural soil quality in these transitional areas.
Objective: To assess the effects of urban expansion on key soil quality parameters including physical, chemical, and biological properties in agricultural soils located within the rural-urban fringe.
Methods: A comparative analysis was conducted across 45 agricultural sites representing three distinct zones: urban-adjacent (0-2 km from urban boundary), transitional (2-5 km), and rural control (>10 km). Soil samples were collected at 0-20 cm and 20-40 cm depths and analyzed for pH, organic matter content, bulk density, nutrient levels, heavy metal concentrations, and microbial activity.
Results: Urban-adjacent agricultural soils showed significant degradation compared to rural controls. Soil organic matter decreased by 32% (p<0.001), bulk density increased by 18% (p<0.01), and heavy metal concentrations exceeded WHO guidelines in 67% of urban-adjacent sites. Microbial biomass carbon was reduced by 45% in areas closest to urban development. Transitional zones exhibited intermediate values, suggesting a gradient effect of urbanization impact.
Conclusion: Urban expansion significantly compromises agricultural soil quality through multiple pathways including contamination, physical compaction, and altered nutrient cycling. These findings highlight the urgent need for sustainable land-use planning and soil conservation strategies in rural-urban fringe areas.