The Brazilian Soil Spectral Library data opening

Abstract

Among the various repositories of soil spectral data, the Brazilian Soil Spectral Library (BSSL, https://bibliotecaespectral.wixsite.com/english), created and maintained by the GeoCiS research group, is representative of the pedodiversity of the region, since it combines soil spectra from agricultural and environmental research. The BSSL database contains 16,084 observations with soil-harmonized surface layer physicochemical and spectral data in the visible, near-infrared, short-wave infrared (Vis-NIR-SWIR, 350–2,500 nm) and mid-infrared (MIR, 4,000–600 cm-¹) ranges from all 26 Brazilian states and the Federal District. The idea of creating the BSSL was born in 1995, completed in 2019 and opened to users in 2023. This database is currently available online at https://zenodo.org/records/8361419. During oppening process, data filtering was performed to ensure reliable and valuable information provided to society. Then consistency and quality assessments were executed using Pearson's correlation and the Cubist algorithm in the R environment. Modeling analysis revealed the robust predictive power of the spectral database, facilitating the modeling of key soil attributes. An open-access BSSL will help researchers validate their results by comparing measured data with predicted data, enabling the development of new models or the improvement of existing ones. The BSSL is a globally significant spectral library due to its broad coverage and representation of different tropical soil classes. Soil spectral data can help governments and corporations by providing information to decision-makers regarding the conservation or exploitation of natural resources to monitor soil health.