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| Tavares Filho,João; Melo,Thadeu Rodrigues de; Machado,Wesley; Maciel,Bruno Vieira. |
| Soils are the foundation of terrestrial ecosystems and their role in food production is fundamental, although physical degradation has been observed in recent years, caused by different cultural practices that modify structures and consequently the functioning of soils. The objective of this study was to evaluate possible structural changes and degradation in an Oxisol under different managements for 20 years: no-tillage cultivation with and without crop rotation, perennial crop and conventional tillage, plus a forested area (reference). Initially, the crop profile was described and subsequently, 10 samples per management system and forest soil were collected to quantify soil organic matter, flocculation degree, bulk density, and macroporosity. The results... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Profile; Soil physical properties; Organic matter; Soil quality. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400025 |
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| Melo,Thadeu Rodrigues de; Machado,Wesley; Tavares Filho,João. |
| ABSTRACT: Few approaches have been developed to measure the isolated effect of exchangeable cations on clay dispersion in soils. In this study, the charge sparsity (CS) index was proposed using the ratio between the cations hydrated ionic radius and valence. The index capacity to measure cation effects on clay dispersion in soils was also evaluated. Three Ferralsols, sampled at different sites in Paraná State, Brazil, were homoionized with Ca2+, Mg2+, K+, or Na+ prior to evaluation of the clay dispersion degree. Published independent data for two soils and clays were also used. We tested the capacity of CS and II, the latter proposed by Marchuck and Rengasamy (2011), to predict clay dispersion in soils. The CS predicted the dispersion degree more... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Colloids; Electrical double layer; Aggregation; Flocculation; Zeta potential. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000101400 |
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