@article{fdi:010085332,
  title = {{F}ield-scale spatial correlation between soil and {V}is-{NIR} spectra in the {C}errado biome of {C}entral {B}razil},
  author = {de {O}liveira, {J}. {F}. and {B}rossard, {M}ichel and {C}orazza, {E}. {J}. and {G}uimaraes, {M}. {D}. and {M}archao, {R}. {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{V}isible and near-infrared ({V}is-{NIR}) spectroscopy is a tool to determine soi l spatial variability and has been used to map soils and their properties. {C}onsidering that physical , chemical , mineralogical , and morphological soi l properties can affect the intensity and the depth of the spectral reflectance band in the {V}is-{NIR} region, the objectives of this work were to: (i) evaluate the potential of the reflectance inflection difference ({RID}) to discriminate soils; and (ii) veri f y potential spatial correlations of the {RID} with soi l properties, compared with the f u l l spectra, in order to build thematic maps at a fiel d scale. {I}n a farm of 375 ha, 78 soil samples from the 0.87-0.92-m depth were collected in a regular grid of 200 m, with a focus on the soi l diagnostic horizon ({B}w horizon). {T}he sampled soils were a {L}atossolo {V}ermelho-{A}marelo & {PRIME};acrico ({H}aplic {F}erralsol) and a {L}atossolo {V}er-melho distr & {PRIME};ofico ({R}hodic {F}erralsol). {T}wenty-two physical , chemical , mineralogical , and morphological soi l properties were determined, and the {V}is-{NIR} spectra between 400 and 2500 nm were measured. {C}onsidering the presence of an inflection band and its relationship with soi l properties, the spectral bands used to calculate the {RID} were between (base 1/base 2): 400-510, 730-930, 1290-1450, 1800-1950, 2000-2218, and 2218-2290 nm. {T}he {RID} failed to map the spatial variability of soi l properties, with a {K}appa inde x of 39%; therefore, it is not a good parameter for building thematic maps of soi l parameters. {I}n addition, the complete spectru m (mainly in 400-510, 730-930, 1290-1450, 1800-1950, 2000-2218, and 2218-2290 nm) was better spatially correlated with soi l properties than the decomposition of the spectrum by the {RID}. {S}oi l classification and level of dis-cretization as affected by spectral variability were also discussed here. {T}hree soi l groups were discriminated mainly by the {K}i and {K} r indexes and clay content. {M}oreover, the variability of the spectra was conditioned by the spatial variability of the mentioned variables. {T}he clay content for soils with a discrepant particle size (group 1 compared with groups 2 and 3) and the {K}i and {K} r indexes for soils with a homogeneous particle size (between groups 2 and 3), associated with the f u l l {V}is-{NIR} spectral analysis, allowed building thematic maps with a good precision, without the need of mathematical models; this was possible by the modification of the reflectance intensity and the size of the concavity of the spectral band.},
  keywords = {{K}i and {K} r indexes ; {R}eflectance inflection difference ; {S}oil spatial variability ; {S}oil spectra ; {BRESIL} ; {GOIAS} ; {PLANALTINA}},
  booktitle = {},
  journal = {{G}eoderma {R}egional},
  volume = {30},
  numero = {},
  pages = {e00532 [13 ]},
  ISSN = {2352-0094},
  year = {2022},
  DOI = {10.1016/j.geodrs.2022.e00532},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085332},
}