Quantity-intensity relationship for characterizing ammonium chemistry of Bangladesh soils in reference to clay mineralogy
1998
Egashira, K. (Kyushu Univ., Fukuoka (Japan). Faculty of Agriculture) | Hagimine, M. | Moslehuddin, A.Z.Md.
Ammonium chemistry in surface soils collected from major soil series of Bangladesh was studied in terms of quantity-intensity (Q/I) relationship. Soils were classified according to physiography and parent materials; calcareous floodplain soils were dominated by mica and smectite, while noncalcareous floodplain soils, terrace soils, and hill soils were dominated by mica or kaolinite and lacked smectite as a major clay mineral. Different Q/I parameters were obtained between soils of smectitic and non-smectitic types. Soils of smectitic type had a high potential buffering capacity which kept the equilibrium activity ratio at a low and fixed level. The content of labile ammonium was high and estimate s to increase with increasing addition of NH3+. In contrast, soils of non-smectitic type with a low potential buffering capacity showed a considerable variation of both the e equilibrium activity ratio and labile ammonium content, as affected by the application of NH4+. Based on the ammonium chemistry, expected N-fertilizer application was compared with the prevailing application method
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