Soils provide a range of essential ecosystem services for sustaining life, including climate regulation. Advanced technologies support the protection and restoration of this natural resource. We developed the first fine-resolution spectral grid of bare soils by processing a spatiotemporal satellite data cube spanning the globe. Landsat imagery provided a 30 m composite soil image using the Geospatial Soil Sensing System (GEOS3), which calculates the median of pixels from the 40-year time series (1984-2022). The map of the Earth's bare soil covers nearly 90 % of the world's drylands. The modeling resulted in 10 spectral patterns of soils worldwide. Results indicate that plant residue and unknown soil patterns are the main factors that affect soil reflectance. Elevation and the shortwave infrared (SWIR2) band show the highest importance, with 78 and 80 %, respectively, suggesting that spectral and geospatial proxies provide inference on soils. We showcase that spectral groups are associated with environmental factors (climate, land use and land cover, geology, landforms, and soil). These outcomes represent an unprecedented information source capable of unveiling nuances on global soil conditions. Information derived from reflectance data supports the modeling of several soil properties with applications in soil-geological surveying, smart agriculture, soil tillage optimization, erosion monitoring, soil health, and climate change studies. Our comprehensive spectrally-based soil grid can address global needs by informing stakeholders and supporting policy, mitigation planning, soil management strategy, and soil, food, and climate security interventions.

5 V Dokuchaev Soil Science Institute 119017 Moscow Russia

Agricultural and Food Engineering Department Indian Institute of Technology Kharagpur West Bengal India

Center of Nuclear Energy in Agriculture University of São Paulo Brazil

CSIRO Agriculture and Food Black Mountain ACT Australia

Department of Biological Systems Engineering University of Nebraska Lincoln Lincoln NE 68583 USA

Department of Geography Porter School of Environmental and Earth Sciences Faculty of Exact Science Tel Aviv University Tel Aviv Israel

Department of Soil Science and Soil Protection Faculty of Agrobiology Food and Natural Resources Czech University of Life Sciences Prague Kamycka 129 Suchdol Prague 16500 Czech Republic

Department of Soil Science Faculty of Agriculture Universitas Andalas Kampus Unand Limau Manis Padang 25163 Indonesia

Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 Iran

Department of Soil Science Luiz de Queiroz College of Agriculture University of São Paulo Piracicaba São Paulo Brazil

Department of Soil Water and Ecosystem Sciences University of Florida USA

Department of Soils Federal University of Viçosa Ave Peter Henry Rolfs s n 36570 900 Viçosa Minas Gerais Brazil

GFZ Helmholtz Centre for Geosciences Telegrafenberg A17 14473 Potsdam Germany

GFZ Helmholtz Centre for Geosciences Telegrafenberg A17 14473 Potsdam Germany; Leibniz University Hannover Institute of Earth System Sciences Soil Science Section Herrenhaeuser Str 2 30419 Hannover Germany

Innovative Solutions for Decision Agriculture Rothamsted Campus West Common Harpenden Hertfordshire AL5 2JQ United Kingdom

Institute of Soil Science and Plant Cultivation State Research Institute Czartoryskich 8 24 100 Puławy Poland

Laboratory of Remote Sensing Spectroscopy and GIS Aristotle University of Thessaloniki Greece

LISAH Univ Montpellier AgroParisTech INRAE IRD L'Institut Agro Montpellier France

LISAH Univ Montpellier AgroParisTech INRAE IRD L'Institut Agro Montpellier France; Indo French Cell for Water Sciences IRD Indian Institute of Science Bengaluru 560012 India

National Authority for Remote Sensing and Space Sciences Cairo 11843 Egypt

National Authority for Remote Sensing and Space Sciences Cairo 11843 Egypt; Department of Environmental Management Institute of Environmental Engineering RUDN University 6 Miklukho Maklaya St Moscow 117198 Russia

New South Wales Department of Climate Change Energy the Environment and Water Parramatta NSW 2150 Australia

State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

Sydney Institute of Agriculture and School of Life and Environmental Sciences The University of Sydney Australia

Université Paris Saclay INRAE AgroParisTech UMR EcoSys 91120 Palaiseau France

Citace poskytuje Crossref.org

Frontiers in earth observation for global soil properties assessment linked to environmental and socio-economic factors