Characteristics of Natric Troporthents Occurring in Semi-Arid Ecoregion of Rajasthan

Six representative soil pedons were studied in Jaipur district of Rajasthan comprising part of hot semi-arid ecoregion. The soils although loamy sand in texture exhibited extreme degree of hardness and supported sparse vegetative cover. All pedons were non saline (ECe ranging from 1.32 to 1.82 dSm-1) but distinctly alkali (pHs ranging from 8.4 to 9.8). The exchange complex was dominated by sodium and ESP varied from 30 to 70, generally decreasing with depth. ECe exhibited slight increase with depth while, pHs did not exhibit any definite trend of variation. Among the soluble ions, sodium was most abundant, while among the anions soluble carbonates and bicarbonates were much in excess over chloride and sulphates considered together. All the soils were calcareous and illuviation of CaCO3 was apparent as its content increased with depth. The soils were typical alkali in nature and could be classified as Natric Troporthents. Hitherto such soils have not been reported among the inventory of salt affected soils in India.