ICRAF_ISRIC

ICRAF_ISRIC

Soil spectral libraries from the ISRIC World Soil Reference Collection (58 countries) scanned by ICRAF

VNIR NIR MIR
Global — Africa, Europe, South America, North America, and Asia
4,000+ samples first release (v1) CC-BY

Database access

Data originally provided by:

Available files

Type Filename Link
MIR spectra — CSV (gzip) ossl_mir_v1.3.csv.gz Download
MIR spectra — Parquet ossl_mir_v1.3.parquet Download
Soil lab measurements — CSV (gzip) ossl_soillab_v1.3.csv.gz Download
Soil lab measurements — Parquet ossl_soillab_v1.3.parquet Download
Soil site metadata — CSV (gzip) ossl_soilsite_v1.3.csv.gz Download
Soil site metadata — Parquet ossl_soilsite_v1.3.parquet Download
VisNIR spectra — CSV (gzip) ossl_visnir_v1.3.csv.gz Download
VisNIR spectra — Parquet ossl_visnir_v1.3.parquet Download

Map

Soil site information

  • Coordinates precision: precise, country
  • Sampling depth: various
  • Geography: landuse
  • Variables available (OSSL): 8 out of 8 — see Database description for full schema
  • Populated columns: id.layer_uuid_txt, id.layer_local_c, loc.country_src_txt, layer.sequence_usda_uint16, layer.upper.depth_usda_cm, layer.lower.depth_usda_cm, longitude.point_wgs84_dd, latitude.point_wgs84_dd

Soil laboratory information

  • Total samples: 4,073
  • Properties available (original): 46
  • Properties standardized (OSSL): 18 — summarized in Table 1 below
  • Categories: physical, chemical, hydrological, carbon & nutrients, metal elements
  • Original source: see Database access

Hover over any OSSL code in the table below to see its full description.

Table 1: Summary statistics (mean, SD, percentiles) for OSSL-standardized soil properties.
skim_variable n_missing mean sd p0 p25 p50 p75 p100
ph.h2o_usda.a268_indexpH, 1:1 Soil-Water SuspensionMethod: usda.a268Unit: index 297 6.11 1.40 3.00 5.00 5.90 7.10 10.50
ph.cacl2_usda.a481_indexpH, 1:2 Soil-CaCl2 SuspensionMethod: usda.a481Unit: index 4039 4.99 1.26 3.10 4.00 5.10 6.05 7.90
caco3_usda.a54_w.pctCarbonate, <2mm FractionMethod: usda.a54Unit: w.pct 2956 9.94 16.41 0.00 1.00 2.60 11.60 99.70
oc_usda.c1059_w.pctOrganic Carbon, Total C without CaCO3, N prepMethod: usda.c1059Unit: w.pct 373 1.20 2.66 0.00 0.22 0.48 1.20 60.00
ca.ext_usda.a722_cmolc.kgCalcium, Extractable, NH4OAcMethod: usda.a722Unit: cmolc.kg 401 10.81 15.58 0.00 0.40 3.60 14.90 168.20
mg.ext_usda.a724_cmolc.kgMagnesium, Extractable, NH4OAc, 2M KCl displacementMethod: usda.a724Unit: cmolc.kg 393 2.81 4.69 0.00 0.20 1.00 3.40 68.00
na.ext_usda.a726_cmolc.kgSodium, Extractable, NH4OAc, 2M KCl displacementMethod: usda.a726Unit: cmolc.kg 409 0.62 2.39 0.00 0.00 0.10 0.30 31.60
k.ext_usda.a725_cmolc.kgPotassium, Extractable, NH4OAc, 2M KCl displacementMethod: usda.a725Unit: cmolc.kg 399 0.33 0.57 0.00 0.10 0.20 0.40 9.80
acidity_usda.a795_cmolc.kgAcidity, BaCl2-TEA Extractable, pH 8.2Method: usda.a795Unit: cmolc.kg 2562 1.99 2.95 0.00 0.20 0.90 2.60 25.50
al.ext_usda.a69_cmolc.kgAluminum, Extractable, KClMethod: usda.a69Unit: cmolc.kg 2532 1.58 2.56 0.00 0.00 0.70 2.10 25.30
cec_usda.a723_cmolc.kgCEC, pH 7.0, NH4OAc, 2M KCl displacementMethod: usda.a723Unit: cmolc.kg 419 16.27 16.41 0.00 5.20 11.50 21.60 189.60
sand.tot_usda.c60_w.pctSand, Total, S prepMethod: usda.c60Unit: w.pct 392 38.24 29.15 0.00 11.10 33.00 61.20 99.60
silt.tot_usda.c62_w.pctSilt, Total, S prepMethod: usda.c62Unit: w.pct 339 29.22 20.39 0.00 13.00 25.00 42.50 256.00
clay.tot_usda.a334_w.pctClayMethod: usda.a334Unit: w.pct 333 32.60 22.27 0.00 14.70 30.10 47.00 96.80
bd_usda.a21_g.cm3Bulk Density, <2 mm fraction, CoreMethod: usda.a21Unit: g.cm3 3074 1.26 0.29 0.28 1.10 1.31 1.48 1.89
wr.10kPa_usda.a8_w.pctWater Retention, 1/10 Bar (10 kPa), ClodMethod: usda.a8Unit: w.pct 3145 36.77 13.27 4.40 28.60 36.45 45.62 77.30
wr.33kPa_usda.a9_w.pctWater Retention, 1/3 Bar (33 kPa), ClodMethod: usda.a9Unit: w.pct 3150 31.82 13.34 2.30 22.90 31.40 41.50 71.40
wr.1500kPa_usda.a417_w.pctWater Retention, 15 Bar (1500 kPa)Method: usda.a417Unit: w.pct 3102 21.74 11.44 0.10 12.90 21.90 29.55 56.40

MIR

  • Acquisition mode: Not available
  • Intensity: absorbance
  • Original range: 400-4000
  • Standardized range: 600-4000
  • Instrument: FTS-7000 FT-IR Spectrometer
  • Manufacturer: Bruker Optics (Karsruhe, Germany)
  • Scan accessory: Not available
  • Sample preparation: Air-dried, finely ground <0.1 mm
  • Additional info: Liquid N2–cooled HgCdTe detector; Al as the reference material

MIR plot

VNIR

  • Acquisition mode: Not available
  • Intensity: reflectance
  • Original range: 350-2500
  • Instrument: FieldSpec FR Spectroradiometer
  • Manufacturer: Analytical Spectral Devices (Boulder, CO, USA)
  • Instrument co-scans: 25
  • Scan repeats: 2
  • Scan accessory: Not available
  • Original resolution: 1
  • Sample preparation: Air-dried, Sieved < 2 mm
  • Additional info: Aluminum reflectors; Ten white reference spectra were recorded using calibrated spectralon

VNIR plot

References

  1. Publication 1
  2. Publication 2