Clay Minerals in Some Saline-Sodic Soils of the Indo-Gangetic Alluvial Plains in Punjab

The clay mineralogy of three typical saline-sodic soils representing Kaheru, Langrian and Isri series and an associated cultivated soil, belonging to Balewal series, was investigated by X-ray diffraction and chemical techniques. Illite was the dominant clay mineral in both groups of Soils. The saline-sodic soils were characterized by the presence of smectite as a second dominant mineral; it was, however, not detected in the associated cultivated soil. Minor amounts of chlorite and kaolinite were present in all cases. Imperfect drainage might have resulted in the transformation of illite to smectite in the saline-sodic soils. Illite, kaolinite and chlorite in these soils were probably inherited. The differences in clay mineralogy between saline-sodic and the associated cultivated soils appeared to be pedogenic rather than lithologic.