Characterizing the chemical composition of soil water is an extremely important facet of many environmental studies. The collection, analysis, and interpretation of soil solution composition are major steps in understanding various reactions in soils. Soil solutions have been used to elucidate pedogenic processes, biogeochemical cycles of important nutrients, metal migration across the landscape, fate and transport of environmental contaminants. Techniques for effectively monitoring the movement of pollutants through the unsaturated zone of soils are needed to provide an “early warning” of potential groundwater contamination.

The purpose of this review is to evaluate various in-situ and laboratory techniques of soil solution sampling along with advantages and disadvantages of each of the techniques. In addition, problems and limitations of each of the techniques are discussed.