@article{fdi:010078946,
  title = {{I}mprovement in spectral library-based quantification of soil properties using representative spiking and local calibration : the case of soil inorganic carbon prediction by mid-infrared spectroscopy},
  author = {{B}arth{\`e}s, {B}ernard and {K}ouakoua, {E}rnest and {C}oll, {P}. and {C}lairotte, {M}. and {M}oulin {E}smard, {P}atricia and {S}aby, {N}. {P}. {A}. and {L}e {C}adre, {E}. and {E}tayo, {A}. and {C}hevallier, {T}iphaine},
  editor = {},
  language = {{ENG}},
  abstract = {{M}id-infrared reflectance spectroscopy ({MIRS}) is time- and cost-effective. {I}t was used for quantifying soil inorganic carbon ({SIC}) concentration in {F}rance based on a national library, and performances were evaluated on an independent regional set. {O}ur objective was to improve the accuracy of {MIRS} predictions based on common multivariate regression, through spiking (enrichment of the national library with some representative target samples) with possible extra-weighting (replication of spiking samples) and local calibration (only using calibration samples that are spectral neighbours of each target samples), which have not been fully explored yet, in combination especially. {G}lobal (i.e. common) calibration yielded accurate prediction (standard error of prediction, {SEP}, was approximate to 5 g kg(-1 )which could be improved when the library was completed with spiking samples (optimally 10 samples extra-weighted 40 times; {SEP} = 3.3 g kg(-1)). {U}sing spiking samples only (without the library) yielded slightly less accurate results ({SEP} = 3.6 g kg(-1)). {P}rediction was more accurate using local calibration without spiking, but on a validation set that was reduced because some validation samples lacked calibration neighbours ({SEP} = 2.5-2.7 g kg(-1)). {L}ocal calibration with spiking (optimally 10 samples without extra-weight) yielded somewhat less accurate prediction but for the full validation set when few calibration neighbours were required ({SEP} = 2.7 g kg(-1)), or higher accuracy on the reduced validation set when many neighbours were required ({SEP} = 2.3 g kg(-1)). {T}hese accurate predictions demonstrated the usefulness of representative spiking and local calibration for rendering large soil spectral libraries fully operational, while extra-weighting had no additional benefit. {A}long with more exhaustive spectral libraries, this paves the way for extensive use of {MIRS} for {SIC} determination.},
  keywords = {{D}iffuse reflectance spectroscopy ; {N}ational spectral library ; {C}arbonates ; {F}rance ; {FRANCE}},
  booktitle = {},
  journal = {{G}eoderma},
  volume = {369},
  numero = {},
  pages = {114272 [12]},
  ISSN = {0016-7061},
  year = {2020},
  DOI = {10.1016/j.geoderma.2020.114272},
  URL = {https://www.documentation.ird.fr/hor/fdi:010078946},
}