Solution chemistry of trace elements in arid zone soils

SOLUTION CHEMISTRY OF TRACE ELEMENTS IN ARID ZONE SOILS 

Soil solution is the aqueous phase of soil. It is in the pore space of soils and includes soil water and soluble constituents, such as dissolved inorganic ions and dissolved organic solutes. Soil solution accommodates and nourishes many surface and solution reactions and soil processes, such as soil formation and decomposition of organic matter. Soil solution provides the source and a channel for movement and transport of nutrients and trace elements and regulates their bioavailability in soils to plants. Trace element uptake by organisms and transport in natural systems typically occurs through the solution phase (Traina and Laperche, 1999). 

In addition, dissolved organic carbon (DOC) is also an important soil solution solute affecting speciation and bioavailability of many trace elements in soil solution. Many trace elements and heavy metals complex with dissolved organic carbon. This is especially important in arid and semi-arid environments since high soil pH increases the solubility of organic molecules and accordingly increases concentrations of dissolved organic carbon in soil solution. 

2 CONCENTRATIONS OF TRACE ELEMENTS IN SOIL SOLUTION OF ARID ZONES 

Holland Sludge-soil layer Ultic Haploxeralf 0.011-0.014 2.83-3.15 1.53-2.22 0.76-1.22 

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