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Toma,Maíra Akemi; Owens,Phillip Ray; Silva,Carlos Alberto; Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Curi,Nilton. |
In soil surveys, it is usual to find profiles with an uncommon disposition of horizons. Dark horizons in depth might be either the consequence of erosion and redeposition of soil materials from upslope or an indication of the podzolization process, which forms a spodic horizon. Few laboratory analyses are known to characterize dark subsurface horizons which could allow for the differentiation of spodic from buried A horizons. Some researchers propose C-humic and C-fulvic acid fraction ratios and forms of carbon to analyze characteristics of these horizons. Therefore, this research aimed to characterize dark subsurface horizons found in soils under a Eucalyptus minimum tillage system in the state of Rio Grande do Sul, Brazil, and to relate soil organic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Humic substances; Organic matter; Erosion; Podzolization; Redeposition. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000400334 |
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Silva,Elen Alvarenga; Silva,Carlos Alberto; Silva,Ivo Ribeiro; Marques,João José G. S. M.; Araujo,Elias Frank de; Carvalho,Samara Andrade de; Silva,Sérgio Henrique Godinho; Curi,Nilton. |
No Brasil, boa parte dos plantios florestais tem sido realizada em solos que apresentam algum grau de degradação física, química ou biológica. A proteção ao solo fornecida pelas árvores, em função da deposição de serapilheira, constitui um dos processos de recuperação de áreas degradadas, e, como a matéria orgânica está relacionada com muitos dos atributos físicos, químicos e biológicos do solo, ela se caracteriza como um fator-chave na manutenção da qualidade ambiental de sistemas florestais. Assim, objetivou-se neste trabalho caracterizar frações da matéria orgânica em solos sob cultivo mínimo de eucalipto com diferentes históricos de uso e posições na paisagem. O estudo foi realizado em três hortos florestais (HFs): Terra Dura, Canafístula e Sanga das... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fracionamento químico; Substâncias húmicas; Horizonte A enterrado; Recuperação de áreas degradadas; 13C. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000400011 |
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Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Poggere,Giovana Clarice; Pádua Junior,Alceu Linares; Gonçalves,Mariana Gabriele Marcolino; Guilherme,Luiz Roberto Guimarães; Curi,Nilton. |
ABSTRACT Sulfuric acid digestion analyses (SAD) provide useful information to environmental studies, in terms of the geochemical balance of nutrients, parent material uniformity, nutrient reserves for perennial crops, and mineralogical composition of the soil clay fraction. Yet, these analyses are costly, time consuming, and generate chemical waste. This work aimed at predicting SAD results from portable X-ray fluorescence (pXRF) spectrometry, which is proposed as a “green chemistry” alternative to the current SAD method. Soil samples developed from different parent materials were analyzed for soil texture and SAD, and scanned with pXRF. The SAD results were predicted from pXRF elemental analyses through simple linear regressions, stepwise multiple linear... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil clay fraction; Weathering indices; Random forest; Proximal sensors; Green chemistry. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000401402 |
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Silva,Elen Alvarenga; Gomes,João Bosco Vasconcellos; Araújo Filho,José Coelho de; Vidal-Torrado,Pablo; Cooper,Miguel; Curi,Nilton. |
The scarcity of comprehensive characterizations of soils associated to gentle summit depressions of the Northeastern Brazilian Coastal Plains justifies this work, which had as objective to provide basic information for the more diverse agricultural and non-agricultural uses. For that, representative soils (Spodosols or similar soils) from these environments were selected in Alagoas, Sergipe and Bahia states. This approach included characterization of morphological, mineralogical and micromorphological properties of the soil profiles, employing standard procedures. The morphological characterization corroborated the effect of the podzolization process during the formation of these soils. The mineralogy of the clay fraction of these soils was basically... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sand-quartzous soils; Cementation; Hydromorphism; Podzolization; Barreiras Formation. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542012000500003 |
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Silva,Elen Alvarenga; Gomes,João Bosco Vasconcellos; Araújo Filho,José Coelho de; Silva,Carlos Alberto; Carvalho,Samara Andrade de; Curi,Nilton. |
Os solos associados às depressões de topo dos Tabuleiros Costeiros são diferenciados sob vários aspectos ainda pouco estudados no Brasil. Geralmente, à medida que se aproxima dessas depressões, nota-se que a textura dos solos é mais arenosa e o hidromorfismo, mais acentuado, sendo comum a ocorrência de Espodossolos. Neste contexto, o objetivo deste trabalho foi realizar diferentes extrações de Fe, Al, Si e C orgânico com o intuito de compreender o processo de podzolização em solos associados às depressões de topo dos Tabuleiros Costeiros do Nordeste brasileiro. Foram descritos perfis e coletadas amostras de solo em quatro áreas: Coruripe, AL; Neópolis, SE; Acajutiba, BA; e Nova Viçosa, BA. Nas amostras, determinou-se o teor de Fe, Al e Si pelos extratores... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Translocação; Posição na paisagem solos arenoquartzosos carbono orgânico. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000100002 |
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Ribeiro,Bruno Teixeira; Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Guilherme,Luiz Roberto Guimarães. |
ABSTRACT The X-ray fluorescence (XRF) is an analytical technique for determination of elemental composition of different materials. In soils, the XRF has many pedological, environmental and agronomic applications, mainly after the emergence of portable equipments (pXRF). This technique has been recently adopted and successfully used for soil characterization worldwide, but very rare works have been carried out in soils of developing countries. The soil characterization includes the complete elemental composition determination (nutrients, trace and rare-earth elements) and allows estimating some soil physical and chemical properties. In Brazil, this technique is still incipient, mainly the use of pXRF, however, it can greatly contribute to soil... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil analyses; Soil morphometrics; Soil characterization. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000300245 |
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Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Poggere,Giovana Clarice; Guilherme,Luiz Roberto Guimarães; Curi,Nilton. |
ABSTRACT Portable X-ray fluorescence spectrometer (pXRF) has been recently adopted by the Soil Science community for uses in both field and laboratory, obtaining the total content of several chemical elements in a few seconds. Sulfuric acid digestion is an expensive and time-consuming laboratory analysis that provides contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5, important for soil studies. Due to few pXRF studies in tropical soils, this work aimed to compare contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5 obtained by pXRF with sulfuric acid digestion results, and to evaluate the effects of varying forms of preparing soil samples and scanning with pXRF on the resulting values in Brazilian soils. Soils were scanned in five conditions in-field (in situ) and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil chemical properties; Proximal sensor; Sulfuric acid digestion analysis; Soil properties prediction; Oxides. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542018000100080 |
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