Abstract:
Macro and micromorphological investigations were conducted on selected Xerepts soils
from southern Iran to identify changes in soil characteristics 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.
