Can mid infrared diffuse reflectance analysis replace soil extractions?

Recent developments in infrared spectroscopy and computer software, togethe r with decreasing spectrometer costs, have resulted in an increase in the p otential for soil analysis. Infrared spectroscopy in both the near and mid infrared ranges allows rapid acquisition of soil information at quantitativ e and qualitative, pr indicator, levels for use in agriculture and environm ental monitoring. In this paper, we describe how mid infrared diffuse refle ctance analysis can provide results comparable in accuracy with many tradit ional extractive and digestion laboratory methods in soil studies, with the possibility of either replacing or enhancing them. Examples are given for estimation of lime requirement, organic carbon, exchangeable cations, air-d ry moisture, clay content and biological indicators. Infrared methodology a ppears to have advantages in facilitating some soil analyses that are other wise very time-consuming or expensive, or where spatially dense data is req uired.