53 results

Soil organic matter in highland Leptosols: influence of pasture management on composition and content

Mariana da Luz Potes, Deborah Pinheiro Dick, Ricardo Simão Diniz Dalmolin, Heike Knicker, Alessandro Samuel da Rosa

01/Feb/2010

Burning pastures after the winter is a traditional practice in highland soils, whose main purpose is the regrowth of vegetation. However, the impact of fire, as well as the influence of grazing on the organic matter of Leptosols is still unknown. The purpose of this study was to investigate the composition and content of organic matter in soil profiles from São José dos Ausentes, state of Rio Grande do Sul, and to relate the results with the occurrence of burning […]

Iron oxidation on roots of two rice cultivars in flooded soil solution

G. Nava, H. Bohnen

01/Jun/2002

Rice cropped under waterlogged conditions may present symptoms of nutritional disorders similar to those caused by iron (Fe) toxicity. The symptoms do not occur in the same intensity in all cultivars and are more frequent in modern cultivars. The aim of our study was to evaluate the plant capacity of oxidizing reduced iron (Fe2+)on the root surface in green house conditions, comparing two rice cultivars (BR IRGA 409 and EPAGRI 108) with different degrees of susceptibility to iron toxicity and […]

Relationship between heavy metals adsorption and chemical and physical attributes of soil classes from Brazil

W. S. Araújo, N. M. B. Amaral Sobrinho, N. Mazur, P. C. Gomes

01/Mar/2002

The objectives of this study were to evaluate the parameters from isotherms of Freundlich and Langmüir that best reflect the adsorption of heavy metals in weathered soils, and to identify the relationship between the selected parameters and the chemical, physical and mineralogical attributes of twelve representative soil classes from Brazil.The soils were collected by EMBRAPA-CNPS during various surveys in the Southern, Southeastern and Northern areas of Brazil.The correlation coefficient among dependent variables, obtained through the isotherms of adsorption (parameters of […]

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