The study looked at how acidic and alkaline soils react to urea fertilizer. In acidic soils, pH levels rose quickly after adding urea, while in alkaline soils, pH levels initially rose, then fell before rising again. Ammonia levels peaked between the 7th and 9th day in acidic soils, but on the 3rd day in alkaline soils. Ammonium and nitrate levels in all soils peaked after 2-4 weeks of urea application. In acidic soils, aluminum levels decreased with higher urea concentrations, leading to lower exchangeable aluminum content in the short term.