Assessment of the impact of kerosene and diesel on soil nitrogen mineralisation
African Journal of Agricultural Research
Department of Microbiology, Federal University of Technology, P.M.B.1526, Owerri, Imo State, Nigeria
Effects of different concentrations (1, 2 and 5% v/w) of diesel and kerosene on N mineralization were studied in a sandy loam soil. Relative to the untreated soil, higher ammonium-N levels were obtained in samples treated with all the concentrations of kerosene and diesel from the second and third weeks of incubation respectively while extents of nitrate-N production differed. Net N-mineralization was 17.211 mg mineral-N/kg soil in untreated soil and -11.753 mg mineral-N/kg soil and -26.562 mg mineral-N/kg soil respectively in soils treated with 5% kerosene and diesel after six weeks incubation. Net nitrification was 29.90 mg NO 3-N/kg soil in untreated soil and -9.35 mg NO 3-N/kg soil and -22. NO 3-N/kg soil respectively in soils treated with 5% kerosene and diesel after six weeks incubation. Overall mineralization rates were highest (13.01 mg N/kg soil per week) in untreated soil. Rates were lower in diesel than in kerosene treated soils. Inhibition of net N mineralisation ranged from of 139.31 to 168.29% and 90.41 to 254.34% after sixth week incubation for kerosene and diesel-treated soils respectively. The toxicity of diesel and kerosene treatment on nitrogen mineralization in the soil is due more to their effects on ammonium-N than on nitrate-N production. © 2011 Academic Journals.