Genesis and Morphological Changes of Soils under Irrigated Date Palm in Southern Iran

Macro and micromorphological investigations were conducted on selected Xerepts soils from southern Iran to identify changes in soil haracteristics with time. Soil samples from similar pedons of four irrigated orchards ranging in age from 20 to 100 years were studied and compared with soil samples of a pedon of non-irrigated land. In addition to routine analyses, undisturbed blocks of soils from each horizon of pedons were prepared and used for micromorphological studies. Field data, micromorphological obsrevations and laboratory data, permitted an overview of changes in soil characteristics and their role in the pedogenesis. Changes observed include the type and distribution pattern of voids, translocation and accumulatin of CaCO3, and the soil fabrics. Calcitic hypocoatings, and compound dense complete calcite infillings in vughs, and large voids were attributed to precipitation as induced by irrigation. There seems to be an increase in organic matter content with time. This needs to be further studid to establish condition for carbon sequestration and increased soil quality in arid regions