ASIC CATIONS INCOASTALPLAIN SAND PARENT MATERIAL

Acid rain significantly impacts soil chemistry, particularly the availability of essential basic cations such as calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺), and potassium(K⁺). This study examines the effect of acid rain on soil basic cations within coastal plains and parent material at three locations in the University of Benin, Edo State, Nigeria. Soil samples were collected from two depths (0-30 cm and 30-60 cm) in three different locations and were analyzed for some soil physical and chemical properties using standard procedure, while rain water samples were collected from the same locations and were analyzed for pH. The results indicated a general decrease in soil pH with depth, with JSQ showing the highest mean pH (5.65), followed by Hall 2 (5.31) and AGR305(5.10). The lowest pH (4.77) was recorded at 30-60 cm in AGR 305, suggesting increased acidification and leaching effects. Exchangeable cation analysis revealed calcium as the dominant cation, with mean values of 0.73 cmol/kg at JSQ, 0.64 cmol/kgat Hall 2, and 0.57 cmol/kg at AGR 305. Magnesium levels ranged from0.14to0.32cmol/kg, with JSQ (0.26 cmol/kg) near the critical threshold (0.2 cmol/kg), while Hall 2(0.19 cmol/kg) and AGR 305 (0.18 cmol/kg) indicated possible deficiencies. Sodium and potassium levels remained close to the critical limits across all locations, with potassium at 0.23 cmol/kg in JSQ, 0.17 cmol/kg in Hall 2, and 0.16 cmol/kg in AGR305.