High-throughput diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is an increasingly valuable technique used to reduce analytic costs, time, and labor when measuring soil properties. This technique can be used to analyze soil variables in large datasets for precision agriculture and landscape-to-watershed scales studies, and therefore help to increase the sustainability of agro-ecosystems.
Some attractive features of DRIFTS are:
- Infrared (IR) ability to simultaneously characterize physical, chemical, and biological properties using a single spectrum.
- Use in the lab or in situ (benchtop or portable spectrometers, respectively).
- Minimum sample preparation (e.g. drying and grinding).
- Cost- and time-effective as well as an environmentally friendly technique (no chemicals and contaminated samples).
The utility of DRIFTS is that specific molecular bonds and vibration behaviors absorb infrared light at a specific, characteristic frequency, enabling identification (and ideally, quantification) of molecular bond types, known as functional groups. Thus, an absorbance spectrum exhibits peaks that represent absorption of infrared light at frequencies (commonly depicted as wavenumbers, cm-1) specific to the type and behavior of functional groups. DRIFTS offers two possibilities for the study of soils:
(1) Qualitative: compositional analysis by functional group types, which enables evaluating, for example, organic matter chemistry
(2) Predictive: calibrating and validating data sets to predict soil properties, such as soil texture and soil organic matter content
DRIFTS applications include:
- Prediction of soil properties.
- Qualitative analysis of soil composition.
- Enhanced visualizations of soil profile.
Our specific objectives include:
- Creating soil spectral libraries of visible, near, middle infrared spectroscopy of soils from different physiographic regions of the Midwest USA.
- Determining suitable experimental parameters to optimize analytical and predictive applications of plate-based high-throughput DRIFTS for soil variables
The Ohio State University:
Dr. Leonardo Deiss, Lead Investigator
Thomas Doohan, Graduate Student
University of Illinois Urbana-Champaign:
Bethany Herman, Soil Fertility Lab Manager
Mason Gingery, Soil Fertility Lab Research Assistant
Madison Campbell, Soil Fertility Lab Research Assistant
The School of Environment and Natural Resources, The Ohio State University