Diffuse reflectance spectroscopy in soil science: new ideas, approaches and strategies
Convener: Raphael Viscarra Rossel  | Co-Convener: César Guerrero 
Oral Programme
 / Thu, 07 Apr, 13:30–17:00  / Room 9
Poster Programme
 / Attendance Thu, 07 Apr, 17:30–19:00  / Display Thu, 07 Apr, 08:00–19:30  / Halls X/Y

The use of visible (Vis), near-infrared (NIR) and mid-infrared (mid-IR) diffuse reflectance spectroscopy (DRS) in soil science and land resource assessment has attracted much attention over the last ten years. This is reflected by the large numbers of papers on both Vis-NIR and mid-IR in the scientific literature over this period.
Soil Vis-NIR and mid-IR techniques are integrative in that they contain information on both organic and inorganic soil composition, which make them particularly useful for determining various physical, chemical and biological soil properties. Advances in chemometrics and computing power have allowed to extract such information from the spectra by modelling of complex relationships that exist in these data.
DRS has some important advantages over conventional soil analysis. For example, the techniques are non-destructive, they are highly reproducible, they are rapid, cost effective, easy to operate, a single spectrum can produce information on various soil properties, small quantities of sample are needed for analysis, they require minimal sample preparations, and they do not require the use of environmentally harmful chemicals. Hence the techniques can be also used to provide quantitative information for input into environmental and soil process models and digital soil mapping.

The objective of this session is to bring together soil and land resource scientists working with Vis, NIR, and mid-IR diffuse reflectance spectroscopy. This session will provide an opportunity to share experiences, establish current knowledge, describe the many applications, present recent advances, new strategies, and discuss future possibilities for research and adoption of the techniques. We especially welcomed abstracts dealing with new ideas, approaches and strategies for a better understanding and applicability of DRS techniques.

This session deals with the following topics:

* Provision of soil information for soil resource assessment and mapping
- Laboratory-based Vis-NIR and mid-IR DRS for rapid estimation of soil properties (chemical, physical, biological)
- Proximal and remote soil sensing (i.e. field based) using Vis-NIR and mid-IR frequencies
- Estimation of soil organic carbon (type, quality and quantity)
- Estimation of soil mineral composition
- Soil classification by Vis-NIR and mid-IR DRS
- Quantification of environmental impacts on soils, e.g. soil degradation and rehabilitation
- Precision agriculture
- Biogeochemical processes in soils
- Characterization of composting and organic wastes
- etc.

* Technical aspects
- Evaluation of the effect of sample preparation on measurement accuracy
- Global vs Local calibrations for soil properties
- Strategies for the extrapolation of calibrations to different spatial scales
- Strategies to link spectroscopic data from different sources (lab-, field- and remote sensing)
- Empirical vs theoretical approaches during modelling of soil properties
- The spectrum as an integration of physical, chemical and biological soil properties
- Non-linear methods of calibration
- Calibration transfers
- Quantifying uncertainty in models and predictions
- Chemometrics
- Data mining
- etc.

* Instrumentation
- laboratory spectrometers
- portable spectrometers
- etc.