Majid Baghernejad
College of Agriculture
Shiraz University, Iran
E-mail: nafissis@sums.ac.ir

Spreading floodwater on arid lands is a new widespread experimental technique that is in progress in several parts of Iran. Intensive short period rainfalls, characteristic of arid regions, carry huge amounts of soil particles of various sizes. Damghan playa, where an artificial recharge project is in progress, was selected in order to study the fate of carried suspended and dissolved particles of clay, calcium carbonate, and gypsum. This playa is located 30 km east of Damghan city. The main objective of this investigation was to determine the effects of artificial recharge system on transportation of soil particles and their subsequent redeposition in soils. Calcareous and gypsiferous parent materials of the region were found to be the source of clay, calcium carbonate, and gypsum particles carried by floodwater. Physico-chemical properties and micromorphological characteristics of soils were determined in order to study distribution and redeposition of these particles in soil profiles. Results of this investigation showed some physico-chemical and micromorphological changes in soils. Changes included translocation in addition to calcium carbonate, gypsum, and clay particles; type and distribution of voids; reduction in soil permeability; formation of cutans and calcitans; calcite hypocoatings; and calcite infillings of voids. Deposited particles caused plugging of large voids.