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| Vendrame,Pedro R.S.; Brito,Osmar R.; Guimarães,Maria F.; Martins,Éder S.; Becquer,Thierry. |
| The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55% of Brazilian beef production. Previous investigations have shown that about 70-80% of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1) a surface horizon (0.0-0.2 m) in order to evaluate its fertility and acidity status for pasture, and (2) a subsurface horizon (0.6-0.8 m), used for classification. Most... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cation exchange capacity; Exchangeable aluminum; Phosphorus availability; Soil degradation; Total carbon. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000400026 |
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| Gonçalves,Mariana Gabriele Marcolino; Ker,João Carlos; Oliveira,Fábio Soares de; Ramos,Letícia Onara Silva; Pacheco,Anderson Almeida; Curi,Nilton. |
| ABSTRACT Soils of the semi-arid region of Minas Gerais have small depth; hard, very hard or even extremely hard consistency when dry and very plastic and very sticky when moist; columnar or angular blocky structure and significant cracking along the profile in the dry period, however they have not been deeply studied yet. Thus, the aim of this study was to detail the genesis of Luvisols in the Semi-arid Depression of the Jequitinhonha Valley (MG), incompassing morphological, physical, chemical, micromorphological and mineralogical attributes, and their relationships. The lack of illuviation coatings in the micromorphological analysis is in line with the expressionless and unclear clay skins observed in the top of the B horizon in only one out of the four... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil mineralogy; Cation exchange capacity; Soil micromorphology.. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542019000100234 |
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| Cunha,Jailson Cavalcante; Ruiz,Hugo Alberto; Freire,Maria Betânia Galvão dos Santos; Alvarez V.,Víctor Hugo; Fernandes,Raphael Bragança Alves. |
| The electrical charges in soil particles are divided into structural or permanent charges and variable charges. Permanent charges develop on the soil particle surface by isomorphic substitution. Variable charges arise from dissociation and association of protons (H+), protonation or deprotonation, and specific adsorption of cations and anions. The aim of this study was to quantify the permanent charges and variable charges of Reference Soils of the State of Pernambuco, Brazil. To do so, 24 subsurface profiles from different regions (nine in the Zona da Mata, eight in the Agreste, and seven in the Sertão) were sampled, representing approximately 80 % of the total area of the state. Measurements were performed using cesium chloride solution. Determination... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clays; Cation exchange capacity; Structural charges; PH dependent charges. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400012 |
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| Cunha,Tony Jarbas Ferreira; Madari,Beata Emoke; Canellas,Luciano Pasqualoto; Ribeiro,Lucedino Paixão; Benites,Vinicius de Melo; Santos,Gabriel de Araújo. |
| Fertility properties, total C (Ctot), and chemical soil organic matter fractions (fulvic acid fraction - FA, humic acid fraction - HA, humin fraction - H) of anthropogenic dark earths (Terra Preta de Índio) of the Amazon basin were compared with those of Ferralsols with no anthropogenic A horizon. Terra Preta soils had a higher fertility (pH: 5.1-5.4; Sum of bases, SB: 8.93-10.33 cmol c kg-1 , CEC: 17.2-17.5 cmol c kg-1 , V: 51-59 %, P: 116-291 mg kg-1) and Ctot (44.6-44.7 g kg-1) than adjacent Ferralsols (pH: 4.4; SB: 2.04 cmol c kg-1, CEC: 9.5 cmol c kg-1, V: 21 %, P 5 mg kg-1, C: 37.9 g kg-1). The C distribution among humic substance fractions (FA, HA, H) in Terra Preta soils was also different, as shown by the ratios HA:FA and EA/H (EA=HA+FA) (2.1-3.0... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Humic substances; Humin fraction; Cation exchange capacity; Total soil carbon. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000100009 |
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| Auler,André Carlos; Pires,Luiz Fernando; Caires,Eduardo Fávero. |
| ABSTRACT Liming represents a management procedure that can affect the soil structure and its thermodynamic processes. In this context, the aims of this study were to assess (i) the effects of the surface and incorporated liming on the clay dispersion, soil water availability, and aeration capacity; (ii) the influence of soil chemical alterations in its physical attributes. For this, a field experiment was installed in a family farming property, located in the southeastern region of the State of Paraná, in a Dystrudept soil. The treatments were 3 application modes (on the surface, incorporated via plowing and incorporated via subsoiling and harrowing), with and without 15 Mg∙ha–1 of lime, aiming to increase the base saturation in the topsoil (0 – 0.20 m) to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water field capacity; Soil acidity; Cation exchange capacity; No-tillage system. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000300433 |
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| Dorneles,Evelyn Penedo; Lisboa,Bruno Brito; Abichequer,André Dabdab; Bissani,Carlos Alberto; Meurer,Egon José; Vargas,Luciano Kayser. |
| Tillage and fertilization methods may affect soil fertility. With the aim of assessing changes in soil chemical properties over a period of ten years, soil samples of a Paleudult were collected over nine seasons at three layer depths (0-5, 5-10, 10-20 cm) and were chemically analyzed. Grain yield and nutrient export in two summer crops, soybean (Glycine max) and corn (Zea mays), in a field experiment set in Eldorado do Sul, in the state of Rio Grande do Sul, Brazil, were determined. Three soil tillage systems were evaluated, conventional (CT), reduced (RT) and no-tillage (NT), combined with mineral (lime and fertilizers) and organic (poultry litter) fertilization. The no-tillage system stood out as compared to the others, especially in the surface layer,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil fertility; Conventional tillage; No-tillage; Organic matter; Cation exchange capacity. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000200175 |
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