Practical applications of ion exchange resins in agricultural and environmental soil research

The use of synthetic ion-exchange resins to examine ion bioavailability in soil and sediment systems has attracted much attention over the years. The first report in this regard was made 7-8 yr after resins were developed in the 1930s. So far, nearly 400 journal articles have been published related to use of resins in soil and environmental studies. The experience gained has led to more widespread applications in research as well as practical use in soil fertility assessment and fertilizer recommendations. Two commercial products developed in North America have directly resulted from years of research efforts. Recent developments in resin technology and availability warrant an updated review of the literature to aid in better understanding and utilizion of this technique. In this paper we provide an overview of historic and current developments in the use of ion exchange techniques in soil research. We also provide specific examples of successful use of batch and diffusion-sensitive ion exchange techniques in research and commercial use to assess ion availability. Finally, we address certain frequently asked questions about how the ion exchange resin technique is applied and how results are interpreted, including their advantages and limitations.