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| Zenero,Mariana Delgado Oliveira; Silva,Laura Fernanda Simões da; Castilho,Selene Cristina de Pierri; Vidal,Alix; Grimaldi,Michel; Cooper,Miguel. |
| ABSTRACT: Knowledge of soils in the Amazon rainforest is becoming increasingly essential due to dynamics adopted by farmers that substitute forest for pastures, together with growing pressure from diverse segments of society towards adoption of sustainable production systems. The objective of this study was to characterize the soils along two toposequences, one under forest (F) and the other under pasture (P), and to verify how the change in land use influences soil attributes, evaluating their inclusion in the Brazilian Soil Classification System (SiBCS). The soils were sampled in pits located at the summit, backslope and footslope positions for morphological, chemical, physical, and clay mineralogy analysis. The results show that the soils are chemically... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Argissolos; Ultisols; Southeast of Pará; Soil classification; Saprolitic character; Aquic with episaturation (epirredóxico) character. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100314 |
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| Medeiros,João Carlos; Cooper,Miguel; Dalla Rosa,Jaqueline; Grimaldi,Michel; Coquet,Yves. |
| Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of 16 point or parametric PTFs reported in the literature on different soils from the south and southeast of the State of Pará, Brazil. The PTFs tested were proposed by Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Parametric PTFs; Point PTFs; Soil physics; Soil water. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000300005 |
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| Macedo,Sônia de Fátima Schilickmann; Grimaldi,Michel; Medina,Cristiane Conti; Cunha,José Edézio da; Guimarães,Maria de Fátima; Tavares Filho,João. |
| ABSTRACT Soil structure plays an important role in water retention, infiltration capacity, porosity, and penetration resistance. The aim of this study was to evaluate the unsaturated hydraulic conductivity and physical properties of Oxisol soils (bulk density and macro-, micro-, and total porosity) in the structures identified using the profil cultural method in areas under two different management practices (perennial pasture and sugarcane). Three pits were dug in each plot to find out how homogeneous morphological structural units (HMSU) were organized in the soil. Next, unsaturated hydraulic conductivity (Ki) was measured in situ inside each HMSU using a triple-ring infiltrometer at multiple suction. Six samples were collected (two samples for each kind... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil use; Compaction; Soil bulk density; Soil porosity. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100524 |
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| Tavares Filho,João; Grimaldi,Michel; Tessier,Daniel. |
| Normalmente a utilização agrícola dos solos é realizada com máquinas e implementos pesados que lhes causam compactação, responsável por afetar a disponibilidade de ar e de água para as plantas. O objetivo deste trabalho foi estudar o comportamento de agregados de Latossolo Amarelo da Amazônia sob compressão mecânica, submetidos a quatro níveis de umidade. Amostras de solo, úmidas e indeformadas, coletadas sob floresta, no horizonte A, a 10 cm de profundidade, e no horizonte B, a 150 cm de profundidade, foram utilizadas neste trabalho. No laboratório, essas amostras foram fragmentadas e peneiradas para obtenção de agregados de 2 a 3 mm de diâmetro, os quais foram colocados em equilíbrio com umidade de quatro potenciais matriciais para, após essa etapa,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Compressão edométrica; Índice de vazios; Porosidade total; Compressão de solo; Compactação de solo. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832005000400001 |
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