Mobile Laser-Induced Breakdown Spectroscopy for Future Application in Precision Agriculture-A Case Study

Area of Science:

• Agricultural Science
• Analytical Chemistry
• Geoscience

Background:

• Precision agriculture relies on accurate soil parameter estimation for targeted interventions like site-specific fertilization.
• Laser-induced breakdown spectroscopy (LIBS) offers a potential method for rapid, in-situ soil analysis.

Purpose of the Study:

• To evaluate the efficacy of LIBS for determining various soil parameters, including macro- and micronutrients, soil organic matter, and texture.
• To compare the performance of handheld and platform LIBS spectrometers against a lab-based instrument for in-field applicability.

Main Methods:

• Investigated 68 soil samples using handheld, platform, and lab-based LIBS instruments.
• Applied multivariate statistical methods, including feature selection and regression techniques (PLS, PCR, SVM, Lasso, Gaussian processes), for soil parameter prediction.
• Compared LIBS results with laboratory analysis for validation.

Main Results:

• Excellent prediction accuracy was achieved for potassium (K), iron (Fe), and clay content.
• Good prediction accuracy was observed for calcium (Ca), magnesium (Mg), phosphorus (P), manganese (Mn), copper (Cu), and silt content.
• Field-deployable LIBS instruments provided reliable results comparable to the high-resolution lab spectrometer, indicating potential for in-field application.

Conclusions:

• LIBS is a viable technique for the rapid, in-situ estimation of essential soil parameters in precision agriculture.
• The successful transfer of LIBS methodology to field measurements facilitates targeted nutrient management and optimized fertilization strategies.
• This study demonstrates the potential of LIBS for enhancing soil analysis efficiency and supporting sustainable agricultural practices.