CAF

CAF

Soil spectral library for Central Africa (CAF)

VNIR NIR MIR
Regional — Africa
1,000+ 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

Map

Soil site information

  • Coordinates precision: precise, region
  • Sampling depth: various
  • Geography: landuse
  • Variables available (OSSL): 19 out of 20 — see Database description for full schema
  • Populated columns: id.layer_uuid_txt, id.layer_local_c, id.loc_src_txt, loc.country_src_txt, loc.country_src_code, loc.province_src_txt, loc.subdiv.name_src_txt, loc.subdiv.type_src_txt, observation.date_src_yyyy.mm.dd, layer.upper.depth_usda_cm, layer.lower.depth_usda_cm, longitude.point_wgs84_dd, latitude.point_wgs84_dd, location.point.error_any_m, site.alt_src_m, site.land.use_src_txt, site.crop_src_txt, site.forest_src_txt, layer.sequence_usda_uint16

Soil laboratory information

  • Total samples: 1,852
  • Properties available (original): 18
  • Properties standardized (OSSL): 15 — summarized in Table 1 below
  • Categories: physical, chemical, 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
c.tot_usda.a622_w.pctCarbon, Total NCSMethod: usda.a622Unit: w.pct 184 1.98 2.51 0.08 0.89 1.38 2.31 45.54
n.tot_usda.a623_w.pctNitrogen, Total NCS, usda.a623Method: usda.a623Unit: w.pct 168 0.16 0.18 0.01 0.07 0.11 0.18 2.92
ph.h2o_usda.a268_indexpH, 1:1 Soil-Water SuspensionMethod: usda.a268Unit: index 1317 5.10 0.94 3.32 4.51 4.84 5.36 8.56
clay.tot_usda.a334_w.pctClayMethod: usda.a334Unit: w.pct 1262 34.63 21.73 1.04 12.41 34.88 51.59 86.88
silt.tot_usda.c62_w.pctSilt, Total, S prepMethod: usda.c62Unit: w.pct 1309 23.85 14.97 4.00 13.48 19.28 29.87 74.75
sand.tot_usda.c60_w.pctSand, Total, S prepMethod: usda.c60Unit: w.pct 1309 42.30 23.77 1.30 21.12 40.50 61.12 89.90
al.ext_aquaregia_g.kgAluminum, Extractable, Aqua RegiaMethod: aquaregiaUnit: g.kg 1128 25.20 24.69 0.16 7.94 12.37 36.24 121.32
fe.ext_aquaregia_g.kgIron, Extractable, Aqua RegiaMethod: aquaregiaUnit: g.kg 1128 38.84 39.55 0.34 10.15 20.13 59.62 352.66
ca.ext_aquaregia_mg.kgCalcium, Extractable, Aqua RegiaMethod: aquaregiaUnit: mg.kg 1128 634.26 1352.25 0.00 52.50 186.94 589.29 19922.26
mg.ext_aquaregia_mg.kgMagnesium, Extractable, Aqua RegiaMethod: aquaregiaUnit: mg.kg 1128 800.40 1425.40 9.27 79.37 141.16 836.50 9500.41
k.ext_aquaregia_mg.kgPotassium, Extractable, Aqua RegiaMethod: aquaregiaUnit: mg.kg 1128 616.41 1020.57 7.96 77.21 163.31 795.00 8073.54
mn.ext_aquaregia_mg.kgManganese, Extractable, Aqua RegiaMethod: aquaregiaUnit: mg.kg 1128 480.73 934.36 2.23 30.09 64.16 455.98 6468.45
na.ext_aquaregia_mg.kgSodium, Extractable, Aqua RegiaMethod: aquaregiaUnit: mg.kg 1128 69.57 128.62 0.00 4.99 13.99 71.72 1213.29
p.ext_aquaregia_mg.kgPhosphorus, Extractable, Aqua RegiaMethod: aquaregiaUnit: mg.kg 1128 534.89 773.33 13.90 130.72 214.20 580.34 6679.17

MIR

  • Acquisition mode: Not available
  • Intensity: absorbance
  • Original range: 600-7500
  • Standardized range: 600-4000
  • Instrument: VERTEX 70 FT-IR
  • Manufacturer: Bruker Optics GmbH (Germany)
  • Scan accessory: Not available
  • Sample preparation: Ground < 50 μm
  • Additional info: A gold coated reflectance standard (Infragold NIR-MIR Reflectance Coating, Labsphere) was used as a background material

MIR plot

References

  1. Publication 1