Mineral alteration and genesis of Al–rich soils derived from conglomerate deposits in Cabo Basin, NE Brazil

Silva

Cunha

et al. 2019

Agraria

RESUMO:No Planalto Sul Catarinense, correspondendo a região de Lages e municípios no seu entorno, existem poucas informações detalhadas sobre solos desenvolvidos das rochas sedimentares gonduânicas, os quais dominam em grande parte desses municípios. O estudo objetivou caracterizar física, química e mineralogicamente cinco solos desenvolvidos de rochas sedimentares da região de Lages-SC, derivados de diferentes formações geológicas, bem como relacionar a mineralogia da fração argila com os atributos químicos desses solos. Para isso, foram descritas e coletadas amostras de horizontes e camadas de cinco perfis de solos, sendo quatro Cambissolos e um Neossolo. Análises químicas, físicas e mineralógicas de cada perfil de solo foram realizadas. A mineralogia da fração argila foi similar entre os solos, composta de caulinita, argilominerais de camada 2:1, com ou sem polímeros de hidroxi-Al entrecamadas e micas e, ou illitas, com predomínio dos primeiros em três dos cinco solos (perfis 2;3 e 4). A composição mineralógica se mostrou relacionada com a acidez e as principais propriedades químicas dos solos. Todos os solos estudados são muito ácidos, com baixas somas e saturação por bases, elevados teores de carbono orgânico total, de Al trocável e de saturação por Al. Os teores de argila foram mais elevados nos solos derivados de folhelhos (Formações Palermo e Teresina) em relação aos demais.

Section: Relação Entre a Mineralogia E As Características Químicas Dos Solos Estudadosunclassified

Atributos químicos, físicos e mineralógicos de solos derivados de rochas sedimentares do Planalto de Lages-SC, Brasil

Silva

Cunha

et al. 2019

Agraria

“…Kaolinite formed during the mineralogical evolution of the soils can be attributed to the alterations of the feldspars, common in the parent material. Costa et al (2018) described pathways of alteration followed by feldspars, mainly, resulted in kaolinite when studying soil developed from the conglomerate of the Cabo Basin in a similar environment, on the south coast of Pernambuco (Litoral/Mata physiographic unit).…”

Section: Discussionmentioning

confidence: 99%

Relief Position and Soil Properties under Continuous Banana Cropping in Subhumid Climate in Northeast Brazil

Araújo

Filho

et al. 2019

Rev. Bras. Ciênc. Solo

Self Cite

Sequences of thick and eroded soils in hills surfaces are cultivated with banana since the beginning of the last century in the Northeast of Pernambuco (PE), Brazil. Measurements of soil properties depending on soil slope under intensive agricultural cultivation are limited mostly as the pedogenetic approach. This study aimed to identify the dominant soil types, to evaluate morphological, physical, chemical, and mineralogical properties of soil profiles, and link them to the relief position under continuous banana cropping, in the transition Mata-Agreste of PE. Three slope classes and soil profiles were considered: Profile 1 (P1), upper third of the elevation slope; Profile 2 (P2), middle third of the slope; and Profile 3 (P3) lower third. They were opened, described, and soil samples collected from all horizons at a typical slope of the region. Independent of relief position and land use, all soils are deep (>1.50 m) and present the argic horizons (Bt) developed in all steeply sloping surfaces (15-33 %). The Bt horizon presented the highest values of soil bulk density and microporosity. Despite the presence of illite, all the soil profiles showed remarkable degree weathering, are mostly kaolinitic, besides presenting goethite and quartz in the soil clay fraction, and predominance of quartz in the silt and sand fraction. Water-stable aggregates >2 mm were dominant in all the relief positions. Acidity, low cation exchange capacity, and in general, nutrient poverty were observed in the soil profiles, as opposed accumulation of exchangeable cations on the lower third of the slope (P3). However, the soil properties were affected by land use and water erosion. The Ap horizons showed the highest values of pH, exchangeable bases, phosphorus available, and organic carbon due to agricultural practices, while the steepest slope (P2) had the lowest content of clay, phosphorus and mean weight diameter of aggregates, and higher organic carbon content, in the superficial horizon, due to removal and deposition by water erosion. From the upper third to the lower third of the slope, Nitic Acrisol, Haplic Acrisol, and Nitic Lixisol were formed.

“…In the soils of PE (smectitic), BR and CB (kaolinitic with or without smectite and/or vermiculite with hydroxy-Al interlayers) (Almeida et al, 2003;Teske et al, 2013;Cunha et al, 2014;Da Costa et al, 2018), in which were found, respectively, very high, high and low levels of Al-KCl, associated with low levels of Ca 2+ and Mg 2+ (Table 3) the two crops responded to liming in both DW production as in RSL and RSA (Figures 1 and 2). This response occurred due to an increase in the pH, basic cations, mainly Ca 2+ and Mg 2+ , the sum and base saturation, and a decrease in the Al-KCl levels and Al saturation (Table 3).…”

Section: Dmentioning

confidence: 99%

Production of soybean and maize plants cultivated in acid soils with high contents of exchangeable aluminum

Cunha

Ernani

et al. 2019

Agraria

In several Brazilian acid soils, the extractable aluminum with the solution of 1.0 mol L-1 KCl (Al-KCl) may exceed 10 cmol c kg-1 , but in some soils the presence of this element seems to exert little or no interference in the productivity of the plants. The study aimed to evaluate in which conditions the high levels of Al-KCl are related to the toxicity in soybean and maize plants cultivated in greenhouse, and their possible interference in the dry matter production of the same. Also, it aimed at assessing the soil chemical attributes that best identified a probable Al toxicity and the responses of the cultivated plants to liming. Al-KCl is not related to the manifestation of toxicity by the plants, nor did it interfere in the productivity of the plants cultivated in the AC9 and RS soils. On the other hand, the high levels of Al-KCl interfered in the productivity of these plants cultivated in the PE, BR and CB soils, manly in the treatments without limestone. Aluminum saturation, sum and base saturation were the best soil chemical attributes for the identification of Al toxicity and plant response to liming.