Pedogenesis on Coastal Tablelands Area With Low Range Altimetry in Paraíba State

Abstract

Small variations of relief may change drainage and runoff and hence promote the formation of sandy surface horizons and hardened subsurface horizons (fragipans and/or duripans) in Coastal Tablelands soils. This study aimed to investigate the pedogenesis on Coastal Tablelands area with low range altimetry in Paraíba state; secondly, we also sought to contribute to the improvement of the Brazilian Soil Classification System (BSCS). Four soil profiles ware described and collected to be submitted to routine physical and chemical analysis, determination of Fe, Al and Si extracted by sulfuric acid digestion, sodium citratebicarbonate-dithionite and acid ammonium oxalate, sodium pyrophosphate, and mineralogical analysis in the sand and clay fractions by X-ray diffractometry. Optical density of the oxalate extract (ODOE) was also determined; the results were statistically evaluated using the R software. Microrelief variations conditioning differentiated water flows, along with the sandy texture of the surface horizons (A and E) and the lower coarse sand/fine sand ratio in the subsurface horizon, seem to promote clay accumulation in depth in the Spodosols developed on Coastal Tablelands environments. For this soils, the argilluvic (argissólico) character at the subgroup level of the BSCS should be incorporated. In addition, Al amorphous mineral phases and/or poorly crystalline play an important role in the formation of strongly cemented horizons (duripans) of the Spodosols, as also reported by other authors. Finally, the ODOE showed to be an efficient indicator of soils under podzolization process, being possible its use as a taxonomic criterion for classification of Spodosols by the BSCS.

Interaction of Cladoniaceae Lichens With Quartzarenic Neosols in Northeastern Brazil: A Mini Review

“…In a local scale, variation on micro-relief can conditioning different water flux, that associated to sand characteristics of this soil, can favor the deposition of clay in deeper horizons. Assays with oxalate extracts of these soils pointed out it as in podsolization process (Silva et al, 2019).…”

“…This way, the mechanism of interaction between lichen and soil, in tabuleiros of Brazilian Northeast should be investigated, with emphasis to the protection of these remaining areas. As the surrounding areas of this vegetation are dominated by sugar cane plantation (Silva et al, 2019), the role of nitrogen can elucidate the mechanism of action of this product used as chemical fertilizer, as well as the damage that can be caused to the lichens and to the environment.…”

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

“…Simultaneously, the more significant presence of organic matter in the amorphous horizon ortstein (Figure 7b). Both characteristics indicate podzolization (Silva et al, 2019;Schiavo et al, 2020). However, in the contact zone between the Bhm and 2C1 horizons, the humin content is high ( Figure 6).…”

Soil preparation systems and type of fertilization as affecting physical attributes of cohesive soil under eucalyptus in Northeastern Brazil

“…The presence of cohesive layers constrains root growth and plant productivity. These landscapes include the coastal wetlands of the southeast, north, and northeastern regions of Brazil, encompassing a small part of the semi-arid coastal zone, between the states of Rio Grande do Norte and Piauí (Silva et al, 2019).…”