Geostatistical assessment of soil salinity and cropping systems used as soil phytoremediation strategy

Salinity is one of the major problems affecting soils of arid and semi-arid environments. This research, carried out around a Mediterranean wetland area, aimed to assess the spatial distribution of soil properties (salinity, texture fractions, pH, organic matter and % of carbonates) by using soil laboratory and geostatistical analysis to determine an adequate strategy for soil remediation. Ordinary kriging was applied to map soil properties and field observations were used to define land use classes. Better map accuracy was obtained for these soil properties: electrical conductivity (EC) (RMSE = 0.529 dS m-1), clay (RMSE = 9.1%), silt (RMSE = 7.28%) and sand (RMSE = 10.69%). The results suggested an opposite relation between silt and sand and a clear distribution of electrical conductivity of soils. Moreover, comparing with the observed land use classes, plants cultivated around the wetland seem to be distributed due to their tolerance to soil salinity. Permanent crops were restricted to less salinized soil, whereas arable crops were close to saline zones and uncultivated areas appear in the most salinized areas. Cropping systems can be used as an effective strategy for salinity control and phytoremediation.