Effect of Lime and Organic Matter Additions on Inorganic N-Transformation in Soil

Depaitment of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Kalyani-741 235

Manuscript received 1 September 1982, revised 4 September 1984, accepted 18 January 1985

Comparatively higher amount of clay-fixed ammonium and lower amount of exchangeable ammonium were observed in the limed over the uniimed soil. Whereas, much lower amount of clay-fixed ammonium was observed in the starch added limed than in the corresponding unlimed soil. Irrespective of liming, magnitude of fixed ammonium in the starch added soil was much less than either the rice straw or no organic matter treated soil. It is suggested that the heterotrophic microbes utilised a considerable amount of fixed ammonium from the soil resulting a decrease in its amount under limed condition.