African Soil Properties and Nutrients Mapped at 30 m Spatial Resolution Using two‑scale Ensemble Machine Learning

AuthorTomislav Hengl
AuthorMatthew A. E. Miller
AuthorJosip Križan
AuthorKeith D. Shepherd
AuthorAndrew Sila
AuthorMilan Kilibarda
AuthorOgnjen Antonijević
AuthorLuka Glušica
AuthorAchim Dobermann
AuthorStephan M. Haefele
AuthorSteve P. McGrath
AuthorGifty E.Acquah
AuthorJamie Collinson
AuthorLeandro Parente
AuthorMohammadreza Sheykhmousa
AuthorKazuki Saito
AuthorJean‑Martial Johnson
AuthorJordan Chamberlin
AuthorFrancis B.T. Silatsa
AuthorMartin Yemefack
AuthorWendt John
AuthorRobert A. MacMillan
AuthorIchsani Wheeler
AuthorJonathan Crouch
Date of acession2023-11-06T14:21:51Z
Date of availability2023-11-06T14:21:51Z
Date of issue2021
AbstractSoil property and class maps for the continent of Africa were so far only available at very generalised scales, with many countries not mapped at all. Thanks to an increasing quantity and availability of soil samples collected at feld point locations by various government and/or NGO funded projects, it is now possible to produce detailed pan-African maps of soil nutrients, including micro-nutrients at fne spatial resolutions. In this paper we describe production of a 30 m resolution Soil Information System of the African continent using, to date, the most comprehensive compilation of soil samples (N ≈ 150, 000) and Earth Observation data. We produced predictions for soil pH, organic carbon (C) and total nitrogen (N), total carbon, efective Cation Exchange Capacity (eCEC), extractable— phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), sodium (Na), iron (Fe), zinc (Zn)—silt, clay and sand, stone content, bulk density and depth to bedrock, at three depths (0, 20 and 50 cm) and using 2-scale 3D Ensemble Machine Learning framework implemented in the mlr (Machine Learning in R) package. As covariate layers we used 250 m resolution (MODIS, PROBA-V and SM2RAIN products), and 30 m resolution (Sentinel-2, Landsat and DTM derivatives) images. Our fvefold spatial Cross-Validation results showed varying accuracy levels ranging from the best performing soil pH (CCC = 0.900) to more poorly predictable extractable phosphorus (CCC = 0.654) and sulphur (CCC = 0.708) and depth to bedrock. Sentinel-2 bands SWIR (B11, B12), NIR (B09, B8A), Landsat SWIR bands, and vertical depth derived from 30 m resolution DTM, were the overall most important 30 m resolution covariates. Climatic data images—SM2RAIN, bioclimatic variables and MODIS Land Surface Temperature—however, remained as the overall most important variables for predicting soil chemical variables at continental scale. This publicly available 30-m Soil Information System of Africa aims at supporting numerous applications, including soil and fertilizer policies and investments, agronomic advice to close yield gaps, environmental programs, or targeting of nutrition interventions.
URLhttps://hub.ifdc.org/handle/20.500.14297/2705
Languageen
SubjectMachine learning
SubjectSoil properties
TitleAfrican Soil Properties and Nutrients Mapped at 30 m Spatial Resolution Using two‑scale Ensemble Machine Learning
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
African_soil_properties_and_nutrients_mapped_at_30 (1).pdf
Size:
4.65 MB
Format:
Adobe Portable Document Format
Description:
License bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed to upon submission
Description:
Collections