Pedogenesis in the Barreiras Formation Under Climates of Rio Grande do Norte, Brazil

Abstract

In Brazil, the state of Rio Grande do Norte has an important coastal zone and coastal Tableland areas along the Barreiras Formation, but there are few studies to locate and characterize soils with cohesive character. Therefore, this work was carried out to characterize pedons in the western and eastern mesoregions of the state, located in the Barreiras Formation and with different climatic conditions. The profile description and sample collection were carried out in March and April 2016. The characteristics of the profile identified were the sequence of horizons and their depth, soil color, texture, structure, consistency, and transition between horizons. The physical analyzes were of soil density and texture. The chemical analyzes consisted of: pH in water and in KCl, contents of available P, Na+, K+, Ca2+, Mg2+, potential acidity, and total organic carbon. Indices obtained were: base sum, effective cation exchange capacity, cation exchange capacity at pH 7.0, base saturation, exchangeable aluminum saturation, and exchangeable sodium percentage. The profiles were classified up to the fourth categorical level. The mineralogical assembly was identified in the clay fraction of the diagnostic horizons. The identification of the minerals was performed by X-ray diffraction. The pedons of the two regions presented distinct characteristics and pedogenesis, occurring laterization in the pedons of the western mesoregion and podzolization in the pedons of the eastern mesoregion, both without presence of cohesive character as a diagnostic attribute.

Soil Attributes and Their Interrelationships with Resistance to Root Penetration and Water Infiltration in Areas with Different Land Uses in the Apodi Plateau, Semiarid Region of Brazil

“…The silt fraction showed higher surface values and an intermediate degree of pedogenetic development. The study carried out by Rêgo et al [113] corroborates the results pointed out in this study.…”

Association of Post-Barreiras and Barreiras Formation strata and influence on soil genesis, Southern Bahia – Brazil

“…These minerals are common in Brazilian soils, including in Barreiras Formation environments (Moreau et al, 2006a;Cunha et al, 2019). The high regional rainfall also influences the low soil fertility because sandy soils have higher leaching (Rêgo et al, 2019) In the upper horizons, we verified the high presence of Na + , which is explained by the constant action of saline sprays of the coast (Magnago et al, 2013). The upper horizons show Ca 2+ , Mg 2+ , and mainly P concentration (Mehlich-1), this has to do with nutrient cycling (Gomes et al, 2010), favoring the increase of V% in these horizons.…”