Theses and Dissertations


Issuing Body

Mississippi State University


Wijewardane, Nuwan K.

Committee Member

Cox, Michael S.

Committee Member

Zhang, Xin

Date of Degree


Original embargo terms

Embargo 6 Months

Document Type

Graduate Thesis - Open Access


Engineering Technology

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Agricultural and Biological Engineering


Instrumental disparities and soil moisture are two of the key limitations in implementing spectroscopic techniques in the field. This study sought to address these challenges through two objectives. The first objective was to assess Visible-near infrared (VisNIR) and mid-infrared (MIR) spectroscopic approaches and explore the feasibility of transferring calibration models between laboratory and portable spectrometers. The second objective addressed the challenge of soil moisture and its impact on spectra. The portable spectrometers demonstrated comparable performance to their laboratory-based counterparts in both regions. Spiking with extra-weight, was the most effective calibration transfer method eliminating disparities between instruments. The samples were rewetted under nine controlled conditions for the moisture study. Results showed that spiking with extra weights significantly outperformed other techniques and model enhancement was insensitive to the moisture contents. Findings of this study will be helpful for development and deployment of in situ sensors to enable field implementation of spectroscopy.

Available for download on Saturday, June 15, 2024