Genesis of sandstone-derived soils in the Cerrado of the Piauí State, Brazil

Diego Ferreira De Souza,Ronny Sobreira Barbosa,Vanessa Martins,Yuri Jacques Agra Bezerra Da Silva,Romário Porto De Oliveira,Márcio Cleto Soares De Moura

doi:10.4136/ambi-agua.2355

Abstract

This study characterized the morphological, physical and chemical attributes of sandstone-derived soils at the Cerrado of the Piauí State, Brazil, in order to identify evolutionary standards. The study was carried out with five representative soil profiles identified as P1-RY (Typical Flavic Psychotic Neosol - Aquents), P2-PA (Typical Dystrophic Yellow Argisol - Alfisol), P3-RL (Fragmentary Litholic Distrophic Neosol - Psammenit), P4-RQ (Typical Ortic Quartzenetic Neosol - Orthents) and P5-PV (Typical Dystrophic Red Argisol - Ultisol). Soil samples were submitted laboratory analysis described morphologically. In general, the soils presented high sand content, low pH, low content of exchangeable bases and low cation exchange capacity (CEC). Organic matter governed the CEC in most cases, suggesting dependence of organic matter in the supply of charges. These soils showed a low degree of weathering, but with iron of high crystallinity. Thus, the relief and the parent material are the major important soil-forming factors at the Cerrado of the Piauí State. Moreover, these soils are young, with the soils from the Piauí Formation being more evolved. However, the sandstones from the Canindé Group apparently are providing lithological secondary minerals for the soil.

Highlights

The Cerrado biome is home to the main thrust of Brazilian agricultural expansion
There is noticeable soil variability at different levels when compared with the Cerrado of other Brazilian regions
Soil Morphology The soil P1-RY presented the horizons A-2C1-3C2-4C3-5C4-6C5-7C6-8C7-9C8 formed by lithological discontinuity along a 2.0 m depth (Table 1)

Summary

Introduction

The Cerrado biome is home to the main thrust of Brazilian agricultural expansion. Soils consist of representative units of more than a dozen classes and are mostly dystrophic and acid (Pfaltzgraff, 2010). In the state of Piauí, this biome occupies approximately 11.5 million hectares and is worldrenowned for its economic importance as a reflection of its imminent agricultural expansion (Pragana et al, 2012). There is noticeable soil variability at different levels when compared with the Cerrado of other Brazilian regions. This variability, which occurs in response to the interaction between the soil formation factors, suggests major challenges for a conscious agricultural production

Methods

Results

Conclusion