Comprehensive nutrient analysis in agricultural organic amendments through non-destructive assays using machine learning.

Journal: PloS one
PMID:

Abstract

Portable X-ray fluorescence (pXRF) and Diffuse Reflectance Fourier Transformed Mid-Infrared (DRIFT-MIR) spectroscopy are rapid and cost-effective analytical tools for material characterization. Here, we provide an assessment of these methods for the analysis of total Carbon, Nitrogen and total elemental composition of multiple elements in organic amendments. We developed machine learning methods to rapidly quantify the concentrations of macro- and micronutrient elements present in the samples and propose a novel system for the quality assessment of organic amendments. Two types of machine learning methods, forest regression and extreme gradient boosting, were used with data from both pXRF and DRIFT-MIR spectroscopy. Cross-validation trials were run to evaluate generalizability of models produced on each instrument. Both methods demonstrated similar broad capabilities in estimating nutrients using machine learning, with pXRF being suitable for nutrients and contaminants. The results make portable spectrometry in combination with machine learning a scalable solution to provide comprehensive nutrient analysis for organic amendments.

Authors

  • Erick K Towett
    World Agroforestry (ICRAF), Nairobi, Kenya.
  • Lee B Drake
    Department of Anthropology, University of New Mexico, Albuquerque, NM, United States of America.
  • Gifty E Acquah
    Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, United Kingdom.
  • Stephan M Haefele
    Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, United Kingdom.
  • Steve P McGrath
    Department of Sustainable Agricultural Sciences, Rothamsted Research, Harpenden, United Kingdom.
  • Keith D Shepherd
    World Agroforestry (ICRAF), Nairobi, Kenya.