Submitted to: Proceedings of the Australian Society of Soil Science Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 30, 2006
Publication Date: December 3, 2007
Citation: Suarez, D.L. 2007. New considerations and tools in the management of saline soils and waters. Proceedings of the Australian Society of Soil Science Conference. Soil Science Solving Problems. p. 10. Technical Abstract: Water suitability for irrigation and sodicity hazard related to infiltration has been established primarily from laboratory experiments, almost all based on short term column experiments of saturated hydraulic conductivity with waters of decreasing electrical conductivity (EC) and constant sodium adsorption ratio (SAR). In most irrigated areas rain is an important factor in the soil water budget and of the resultant chemical and physical conditions. Calcareous soils from the Upper Great Plains of the U.S. and a non calcareous soil from the arid southwestern U.S. were examined in year- long outdoor studies with conditions of combined simulated rain and irrigation and wetting and drying cycles with waters of varying SAR and at an electrical conductivity of either 1.0 and 2.0 dS/m, and varying pH. There was little difference in the infiltration results from the 2 salinities but significant differences in the SAR treatments. For the final rain infiltration event, there was no significant difference between the control and SAR 2 treatments but decreasing infiltration with increasing SAR for all SAR values above SAR 2. The potential adverse impact of rain events on saline soils is qualitatively known but can be effectively evaluated by UNSATCHEM model simulations of the changes in EC and SAR resultant from rain and irrigation events and quantities, on soils of varying cation exchange capacity and mineralogy. These techniques can be further combined with electromagnetic or resistivity salinity mapping for site specific management, including model simulations of the effects of surface application of varying amounts of gypsum.