iSDA Soil

Date modified: 31 October 2023

Background

Innovative Solutions for Decision Agriculture iSDA soil is an open access soils data resource for the African continent. The key data products are spatial predictions of soil nutrient concentrations and soil properties, derived from predictive soil mapping (PSM) techniques.

Soils data can be useful for a range of applications including land suitability mapping for agriculture, soil amelioration planning (e.g. liming to address acidic soils or fertiliser to address fertility constraints), and for construction or infrastructure planning.

iSDA variables

iSDA offers numerous soil variables shown in the table below. Many of the variables have four layers: mean and standard deviation at 0-20cm and 20-50cm depth. Layers are accessible via their Access Names e.g. ‘bedrock_depth’ in the Sandbox.

Some variables are indexed in Digital Earth Africa, and others can be brought in directly.

Table 1: iSDA soil products available on the DE Africa platform.

Variable

Access Name

Layers

Depth to bedrock

bedrock_depth

0-200cm depth, predicted mean and standard deviation

Bulk density, <2mm fraction

bulk_density

0-20cm and 20-50cm, predicted mean and standard deviation

Carbon, total

carbon_total

0-20cm and 20-50cm, predicted mean and standard deviation

Clay content

clay_content

0-20 cm and 20-50 cm, predicted mean and standard deviation

Sand content

sand_content

0-20cm and 20-50cm, predicted mean and standard deviation

Silt content

silt_content

0-20cm and 20-50cm, predicted mean and standard deviation

Relevant metadata for the iSDA soil products, as well as the specific temporal and geographic extents for the product can be explored as an interactive map on the DE Africa Metadata Explorer. Data is available for the shaded region. A Jupyter Notebook which demonstrates loading and using iSDA soil products in the Sandbox is also available.

Figure 1: iSDA soil bedrock depth geographic extent

iSDA Soil Geographic Extent

Technical information

Spatial prediction of soil properties in the iSDA product suite was undertaken with five regression modelling algorithms. The prediction process utilises field data in combination with covariates such as topographic and surface reflectance data. Further technical information on iSDA products, and links to academic papers describing the methodology, can be found on the iSDA technical information page.

References

Miller MAE, Shepherd KD, Kisitu B, Collinson J (2021) iSDAsoil: The first continent-scale soil property map at 30 m resolution provides a soil information revolution for Africa. PLoS Biol 19(11): e3001441. https://doi.org/10.1371/journal.pbio.3001441

License and Acknowledgements

This data is licensed under a Creative Commons by Attribution (CC BY 4.0) license.

Credits: iSDA

Product Details

The specifications for the six products listed above in Table 1 are described in succession below.


1. iSDA Soil Bedrock Depth

Product Overview

Soil bedrock depth can be useful for development planning, such as agricultural developments or construction.

Specifications

Table 2: iSDA soil bedrock depth product specifications

Specification

Product name

isda_soil_bedrock_depth

Cell size - X (metres)

30

Cell size - Y (metres)

30

Coordinate reference system

EPSG:3857

Update frequency

None

Measurements

Table 3: iSDA soil bedrock depth product measurements

Band ID

Description

Units

Data type

No data\(^\dagger\)

mean_0_200

Soil bedrock depth, mean prediction 0-200cm

cm

float32

NaN

stdev_0_200

Soil bedrock depth, prediction standard deviation 0-200cm

cm

float32

NaN

Media and example images

Figure 2: iSDA soil bedrock depth (cm) for an area near Cape Town, South Africa.

iSDA Bedrock Depth

Data Access

Amazon web services S3

iSDA layers are available in AWS S3, details below. iSDA has published documentation on accessing data through AWS.

Table 4: iSDA depth to bedrock access details through AWS.

AWS S3 details

Product

bedrock_depth

Bucket ARD

arn:aws:s3:::isdasoil

Region

us-west-2

Open Data Cube (ODC)

The iSDA soil depth to bedrock product can be accessed through the Digital Earth Africa ODC API, which is available through the Digital Earth Africa Sandbox.

ODC product name: isda_soil_bedrock_depth

The isda_soil_bedrock_depth has two layers: the estimate itself and standard deviation as a measure of prediction uncertainty. They can be called by using the default name or by the band’s alternative name as listed in the table below.

Table 5: iSDA depth to bedrock band names.

Band name

Alternative names

Fill value

mean_0_200

MEAN_0_200

NaN

stdev_0_200

STDEV_0_200

NaN


2. iSDA Soil Bulk Density

Product Overview

Soil bulk density is a useful variable for understanding soil’s capacity to support ecosystem functions and other uses. It is also a useful input for planning soil additive rates.

Specifications

Table 6: iSDA soil bulk density product specifications

Specification

Product name

isda_soil_bulk_density

Cell size - X (metres)

30

Cell size - Y (metres)

30

Coordinate reference system

EPSG:3857

Update frequency

None

Measurements

Table 7: iSDA soil bulk density product measurements

Band ID

Description

Units

Data type

No data\(^\dagger\)

mean_0_20

Soil bulk density, mean prediction 0-20cm

g/cm\(^3\)

float32

NaN

mean_20_50

Soil bulk density, mean prediction 20-50cm

g/cm\(^3\)

float32

NaN

stdev_0_20

Soil bulk density, prediction standard deviation 0-20cm

g/cm\(^3\)

float32

NaN

stdev_20_50

Soil bulk density, prediction standard deviation 20-50cm

g/cm\(^3\)

float32

NaN

Media and example images

Figure 3: iSDA soil bulk density (g/cm3) for an area near Cape Town, South Africa.

iSDA Bulk Density

Data Access

Amazon web services S3

iSDA layers are available in AWS S3, details below. iSDA has published documentation on accessing data through AWS.

Table 8: iSDA soil bulk density access details through AWS.

AWS S3 details

Product

bulk_density

Bucket ARD

arn:aws:s3:::isdasoil

Region

us-west-2

Open Data Cube (ODC)

The iSDA soil bulk density product can be accessed through the Digital Earth Africa ODC API, which is available through the Digital Earth Africa Sandbox.

ODC product name: isda_soil_bulk_density

The isda_soil_bulk_density has two layers: the estimate itself and standard deviation as a measure of prediction uncertainty. They can be called by using the default name or by the band’s alternative name as listed in the table below.

Table 9: iSDA soil bulk density band names.

Band name

Alternative names

Fill value

mean_0_20

MEAN_0_20

NaN

mean_20_50

MEAN_20_50

NaN

stdev_0_20

STDEV_0_20

NaN

stdev_20_50

STDEV_20_50

NaN


3. iSDA Soil Carbon Total

Product Overview

Total soil carbon is critical to a range of application such as Carbon cycle and Land Degradation Neutrality (LDN) monitoring.

Specifications

Table 10: iSDA soil carbon total product specifications

Specification

Product name

isda_soil_carbon_total

Cell size - X (metres)

30

Cell size - Y (metres)

30

Coordinate reference system

EPSG:3857

Update frequency

None

Measurements

Table 11: iSDA soil carbon total product measurements

Band ID

Description

Units

Data type

No data\(^\dagger\)

mean_0_20

Soil carbon total, mean prediction 0-20cm

g/kg

float32

NaN

mean_20_50

Soil carbon total, mean prediction 20-50cm

g/kg

float32

NaN

stdev_0_20

Soil carbon total, prediction standard deviation 0-20cm

g/kg

float32

NaN

stdev_20_50

Soil carbon total, prediction standard deviation 20-50cm

g/kg

float32

NaN

Back Transformation

Soil carbon total values must be transformed, in Python the transformation can be written as np.expm1(x/10).

Media and example images

Figure 4: iSDA soil carbon total (g/kg) for an area near Lake Tana, Ethiopia.

iSDA Soil Carbon Total

Data Access

Amazon web services S3

iSDA layers are available in AWS S3, details below. iSDA has published documentation on accessing data through AWS.

Table 12: iSDA soil carbon total access details through AWS.

AWS S3 details

Product

carbon_total

Bucket ARD

arn:aws:s3:::isdasoil

Region

us-west-2

Open Data Cube (ODC)

The iSDA soil carbon total product can be accessed through the Digital Earth Africa ODC API, which is available through the Digital Earth Africa Sandbox.

ODC product name: isda_soil_carbon_total

The isda_soil_carbon_total has two layers: the estimate itself and standard deviation as a measure of prediction uncertainty. They can be called by using the default name or by the band’s alternative name as listed in the table below.

Table 13: iSDA soil carbon total band names.

Band name

Alternative names

Fill value

mean_0_20

MEAN_0_20

NaN

mean_20_50

MEAN_20_50

NaN

stdev_0_20

STDEV_0_20

NaN

stdev_20_50

STDEV_20_50

NaN


4. iSDA Soil Clay Content

Product Overview

Soil clay content is one of three (sand, silt, clay) soil texture layers. Soil texture determines many other soil attributes, such as water and nutrient holding capacity.

Specifications

Table 14: iSDA soil clay content product specifications

Specification

Product name

isda_soil_clay_content

Cell size - X (metres)

30

Cell size - Y (metres)

30

Coordinate reference system

EPSG:3857

Update frequency

None

Measurements

Table 15: iSDA soil clay content total product measurements

Band ID

Description

Units

Data type

No data\(^\dagger\)

mean_0_20

Soil clay content, mean prediction 0-20cm

percent

float32

NaN

mean_20_50

Soil clay content, mean prediction 20-50cm

percent

float32

NaN

stdev_0_20

Soil clay content, prediction standard deviation 0-20cm

percent

float32

NaN

stdev_20_50

Soil clay content, prediction standard deviation 20-50cm

percent

float32

NaN

Media and example images

Figure 5: iSDA soil clay content (%) in the Okavango Delta, Botswana.

iSDA Soil Clay Content

Credits: iSDA

Data Access

Amazon web services S3

iSDA layers are available in AWS S3, details below. iSDA has published documentation on accessing data through AWS.

Table 16: iSDA soil clay content access details through AWS.

AWS S3 details

Product

clay_content

Bucket ARD

arn:aws:s3:::isdasoil

Region

us-west-2

Open Data Cube (ODC)

The iSDA soil clay content product can be accessed through the Digital Earth Africa ODC API, which is available through the Digital Earth Africa Sandbox.

ODC product name: isda_soil_clay_content

The isda_soil_clay_content has two layers: the estimate itself and standard deviation as a measure of prediction uncertainty. They can be called by using the default name or by the band’s alternative name as listed in the table below.

Table 17: iSDA soil clay content band names.

Band name

Alternative names

Fill value

mean_0_20

MEAN_0_20

NaN

mean_20_50

MEAN_20_50

NaN

stdev_0_20

STDEV_0_20

NaN

stdev_20_50

STDEV_20_50

NaN


5. iSDA Soil Sand Content

Product Overview

Innovative Solutions for Decision Agriculture iSDA soil is an open access soils data resource for the African continent. The key data products are spatial predictions of soil nutrient concentrations and soil properties, derived from predictive soil mapping (PSM) techniques.

Soil sand content is one of three (sand, silt, clay) soil texture layers. Soil texture determines many other soil attributes, such as water and nutrient holding capacity.

Specifications

Table 18: iSDA soil sand content product specifications

Specification

Product name

isda_soil_sand_content

Cell size - X (metres)

30

Cell size - Y (metres)

30

Coordinate reference system

EPSG:3857

Update frequency

None

Measurements

Table 19: iSDA soil sand content total product measurements

Band ID

Description

Units

Data type

No data\(^\dagger\)

mean_0_20

Soil sand content, mean prediction 0-20cm

percent

float32

NaN

mean_20_50

Soil sand content, mean prediction 20-50cm

percent

float32

NaN

stdev_0_20

Soil sand content, prediction standard deviation 0-20cm

percent

float32

NaN

stdev_20_50

Soil sand content, prediction standard deviation 20-50cm

percent

float32

NaN

Media and example images

Figure 6: iSDA soil sand content (%) in the Okavango Delta, Botswana.

iSDA Soil Sand Content

Data Access

Amazon web services S3

iSDA layers are available in AWS S3, details below. iSDA has published documentation on accessing data through AWS.

Table 20: iSDA soil sand content access details through AWS.

AWS S3 details

Product

sand_content

Bucket ARD

arn:aws:s3:::isdasoil

Region

us-west-2

Open Data Cube (ODC)

The iSDA soil sand content product can be accessed through the Digital Earth Africa ODC API, which is available through the Digital Earth Africa Sandbox.

ODC product name: isda_soil_sand_content

The isda_soil_sand_content has two layers: the estimate itself and standard deviation as a measure of prediction uncertainty. They can be called by using the default name or by the band’s alternative name as listed in the table below.

Table 21: iSDA soil sand content band names.

Band name

Alternative names

Fill value

mean_0_20

MEAN_0_20

NaN

mean_20_50

MEAN_20_50

NaN

stdev_0_20

STDEV_0_20

NaN

stdev_20_50

STDEV_20_50

NaN


6. iSDA Soil Silt Content

Product Overview

Soil silt content is one of three (sand, silt, clay) soil texture layers. Soil texture determines many other soil attributes, such as water and nutrient holding capacity.

Specifications

Table 22: iSDA soil silt content product specifications

Specification

Product name

isda_soil_silt_content

Cell size - X (metres)

30

Cell size - Y (metres)

30

Coordinate reference system

EPSG:3857

Update frequency

None

Measurements

Table 23: iSDA soil silt content total product measurements

Band ID

Description

Units

Data type

No data\(^\dagger\)

mean_0_20

Soil silt content, mean prediction 0-20cm

percent

float32

NaN

mean_20_50

Soil silt content, mean prediction 20-50cm

percent

float32

NaN

stdev_0_20

Soil silt content, prediction standard deviation 0-20cm

percent

float32

NaN

stdev_20_50

Soil silt content, prediction standard deviation 20-50cm

percent

float32

NaN

Media and example images

Figure 7: iSDA soil silt content (%) in the Okavango Delta, Botswana.

iSDA Soil Silt Content

Data Access

Amazon web services S3

iSDA layers are available in AWS S3, details below. iSDA has published documentation on accessing data through AWS.

Table 24: iSDA soil silt content access details through AWS.

AWS S3 details

Product

silt_content

Bucket ARD

arn:aws:s3:::isdasoil

Region

us-west-2

Open Data Cube (ODC)

The iSDA soil silt content product can be accessed through the Digital Earth Africa ODC API, which is available through the Digital Earth Africa Sandbox.

ODC product name: isda_soil_silt_content

The isda_soil_silt_content has two layers: the estimate itself and standard deviation as a measure of prediction uncertainty. They can be called by using the default name or by the band’s alternative name as listed in the table below.

Table 4: iSDA soil silt content band names.

Band name

Alternative names

Fill value

mean_0_20

MEAN_0_20

NaN

mean_20_50

MEAN_20_50

NaN

stdev_0_20

STDEV_0_20

NaN

stdev_20_50

STDEV_20_50

NaN