Soil responses to sodicity and salinity: challenges and opportunities

Exchangeable sodium and low salinity deteriorate the permeability of soils to air and water. The susceptibility of soils to sodicity and low salinity depend on both the inherent properties of the soils (e.g. texture, mineralo gy, pH, CaCO3, sesquioxides, and organic matter content) and extrinsic, tim e-dependent properties (e.g. cultivation, irrigation method and wetting rat e, antecedent water content, and the time since cultivation). Whereas the e ffect of inherent soil properties on the soil response to sodicity has been studied and modelled, especially under laboratory conditions, the effect o f soil management on the physical response of soils to sodicity has been st udied very little. Consequently our ability to predict the changes in soil permeability under field conditions is limited. Including the effect of man agement on the physical response of soils to sodicity and low salinity is t he main challenge facing researchers, consultants, and farmers.