Spodosols in Brazil: distribution, characteristics and diagnostic attributes of spodic horizons

Abstract

Spodosols are reported in specific environments of Brazil, such as sandy materials in the Amazon and Pantanal basin, sandbanks in the coastal fringes and coastal tableland areas, and a few in high-altitude mountains with quartz-rich rocky substrates. This study describes variations in characteristics and attributes of spodic horizons from soils classified as Spodosols in Brazilian pedoenvironments. Data were obtained from the literature, comprising landscape and location, morphological characteristics, physical and chemical attributes of Spodosol profiles, classified by the Brazilian Soil Classification System (SiBCS). The data grouped according to the pedoenvironments demonstrated the predominance of the sand fraction in the spodic horizons. The finer texture influences the organic carbon and sum of bases accumulation. Soils from the Pantanal basin with high pH values and low organic carbon content differ from the central concept of Spodosols and the podzolisation process. The aluminium and iron extractable by selective dissolution indicate higher participation of aluminium in detriment to iron. The establishment of quantitative values in the SiBCS for attributes associated with the podzolisation process is important to correlate with international soil taxonomic systems and global databases.