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Farias,Samuel Christian Cohen; Silva Júnior,Mário Lopes da; Ruivo,Maria de Lourdes Pinheiro; Rodrigues,Possidônio Guimarães; Melo,Vânia Silva de; Costa,Adriane da Rocha; Souza Júnior,João Cardoso de. |
ABSTRACT The use of fire to prepare agricultural areas is a technique still used by small farmers in eastern Amazon. This type of management changes the dynamics of soil nutrients, especially phosphorus, which constitutes the most limiting nutrient for crop production in tropical soils. This study was carried out to evaluate changes in phosphorus forms in an Argissolo Amarelo Distrófico (Ultisol) submitted to burning and trituration of secondary forest in eastern Amazon. The evaluated systems were: slash-and-burn of vegetation; slash-and-mulch of vegetation; and secondary vegetation. The labile, moderately labile, moderately recalcitrant, available and total phosphorus fractions were assessed at the soil depths of 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Shifting cultivation; Tropical soils; Phosphorus fractions; Organic phosphorus. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100506 |
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Mariano,Isabela Orlando dos Santos; Fernandes,Luiz Arnaldo; Faquin,Valdemar; Andrade,Alex Teixeira de. |
Lowland soils present a great potential for the flooded rice crop. This work aimed to estimate critical levels of P in waterlogged soils cultivated with rice using Mehlich 1 and anion exchange resin as soil-P extractors, compare the performance of these extractors as for the evaluation of the P availability, and study the soil-P fractions involved in the P nutrition of the rice crop. Studied soils consisted of four Histosols: Low Humic Gley (GP), Aluvial (A), Humic Gley (GH) and Bog Soil (O) which were previously cultivated with beans. The experimental design was completely randomized, in a factorial scheme, using four soils, five P rates (75, 150, 300, 500 and 800 mg dm-3) and two liming treatments (with and without liming), with three replicates. After... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Phosphorus fractions; Extractors. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000100017 |
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