geodata (version 0.6-2)

soil_af: Soil data for Africa

Description

Download chemical soil properties data for Africa for different soil depths. The spatial resolution is 30 arc-seconds (about 1 km2), aggregated from the original 250m resolution.

There are more recent estimations for some of the properties available in other data sets. See soil_af_isda and soil_world.

For more info, see https://www.isric.org/projects/soil-property-maps-africa-250-m-resolution

The data have a CC-BY 4.0 NC license

Usage

soil_af(var, depth, path, ...)

Value

SpatRaster

Arguments

var

character. Variables name such as "pH" or "clay". See Details

depth

numeric. One of 5, 15, 30, 60, 100, 200. This is shorthand for the following depth ranges: 0-5, 5-15, 15-30, 30-60, 60-100, 100-200 cm. Or one of 20, 50 for 0-20 or 20-50 cm

path

character. Path for storing the downloaded data. See geodata_path

...

additional arguments passed to download.file

Details

	var	description	unit
	clay	Soil texture fraction clay	%
	sand	Soil texture fraction sand	%
	silt	Soil texture fraction silt	%
	coarse	Coarse fragments volumetric	%
	SOC	Organic carbon	g kg-1 (‰)
	BLKD	Bulk density (fine earth)	kg m-3
	poros	Porosity (volum. fraction) based on PTF	-
	AWpF2.0	Avail. soil water capacity (vol. frac.) for FC = pF 2.0	-
	AWpF2.3	Avail. soil water capacity (vol. frac.) for FC = pF 2.3	-
	AWpF2.5	Avail. soil water capacity (vol. frac.) for FC = pF 2.4	-
	AWpF4.2	Avail. soil wat. cap. (vol. frac.) at wilting point (pF 4.2)	-
	BDR	Depth to bedrock	cm
	.	.	.
	pH	pH (H2O)	-
	ECN	Electrical conductivity	mS/m (?)
	acid-exch	Exchangeable acidity	cmol(+) kg-1
	bases-exch	Sum of exchangeable bases	cmol(+) kg-1
	CEC	Cation Exchange Capacity	cmol(+) kg-1
	Al-extr	Extractable Aluminum (Mehlich 3)	mg kg-1 (ppm)
	Al-exch	Exchangeable Aluminum	cmol(+) kg-1
	Ca-exch	Exchangeable Calcium	cmol(+) kg-1
	K-exch	Exchangeable Potassium	cmol(+) kg-1
	Mg-exch	Exchangeable Magnesium	cmol(+) kg-1
	Na-exch	Exchangeable Sodium	cmol(+) kg-1
	Ntot	Total nitrogen	g kg-1

References

Hengl T, Heuvelink GBM, Kempen B, Leenaars JGB, Walsh MG, Shepherd KD, et al. (2015) Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions. PLoS ONE 10(6): e0125814. doi:10.1371/journal.pone.0125814

See Also

soil_af_elements, soil_af_isda, soil_world_vsi

Examples

# \donttest{
# downloads a large file
aph <- soil_af(var="ph", depth=5, path=tempdir())
# }