Soil classes in the Caiabi and Renato river basins, tributaries of the Teles Pires river in the south of the Amazon

Abstract

Due to advances in agricultural production systems and the growing demand for food in the world, the need to investigate the relationships between soil attributes and the different environmental conditions in which they are inserted is still prominent. There are several scientific products that present the characterizations of Brazilian soils, however, depending on the application, the greatest limitations are linked to spatial scales and sampling in isolated regions. In this work, eighteen soil profiles were classified, distributed in two hydrographic basins (Renato and Caiabi rivers), of tributaries of the Teles Pires river, in the southern region of the Amazon. Field work was carried out with the general and morphological description of the horizons and the collection of deformed and undisturbed samples for further physical and chemical analysis in the laboratory. The classification of the 18 soil profiles in the field was compared up to the fourth categorical level with the IBGE data, 2021. The compatibility of the soils classified in the field with the IBGE data was 95% in the order, 38% in the suborder, 95% in the large groups and 88% in subgroups. The predominant soil class in the two hydrographic basins is Oxisol (Latosols), ranging from red to red-yellow, with hues from 2.5 YR to 10.0 YR, all dystrophic. Plinthic horizons were observed in diagnostic positions in the Renato river basin and in non-diagnostic positions in the Caiabi river basin.