This study investigates the impact of highway proximity on soil physicochemical and biological parameters in wheat (Triticum aestivum) and pearl millet (Pennisetum glaucum) cultivation. Soil samples were collected at two developmental stages from control sites (200 m away from the highway) and experimental sites (roadside) for both crops. Key parameters analysed included pH, electrical conductivity (EC), organic carbon (OC), macro-nutrients (K, P, N), total microbial count, dehydrogenase activity (DHA), and alkaline phosphatase (ALP) activity.

Results indicated that roadside soils exhibited increased EC and slightly elevated pH levels compared to control sites, suggesting possible accumulation of vehicular pollutants. Organic carbon content and available potassium and phosphorus were generally lower in roadside soils, particularly in wheat fields. Nitrogen levels showed a decreasing trend at roadside sites across both crops. Microbial activity, reflected in total microbial counts, DHA, and ALP activity, was consistently higher in control sites, particularly for wheat, indicating a negative influence of vehicular emissions on soil biological health.