| Registro completo |
| Provedor de dados: |
Ciência e Agrotecnologia
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| País: |
Brazil
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| Título: |
Adsorption and availability of phosphorus in response to humic acid rates in soils limed with CaCO3 or MgCO3
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| Autores: |
Maluf,Henrique José Guimarães Moreira
Silva,Carlos Alberto
Curi,Nilton
Norton,Lloyd Darrell
Rosa,Sara Dantas
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| Data: |
2018-02-01
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| Ano: |
2018
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| Palavras-chave: |
Organic ligands
Liming
Humic acid-metal-P complexes
Langmuir isotherm
Phosphate maximum buffering capacity.
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| Resumo: |
ABSTRACT Humic acid (HA) may reduce adsorption and increase soil P availability, however, the magnitude of this effect is different when Ca2+ prevails over Mg2+ in limed soils. The objective of this study was to evaluate the effects of HA rates and carbonate sources on the adsorption, phosphate maximum buffering capacity (PMBC), and P availability in two contrasting soils. Oxisol and Entisol samples were firstly incubated with the following HA rates: 0, 20, 50, 100, 200 and 400 mg kg-1, combined with CaCO3 or MgCO3, to evaluate P adsorption. In sequence, soil samples were newly incubated with P (400 mg kg-1) to evaluate P availability. The least P adsorption was found when 296 mg kg-1 of HA was added to Oxisol. Applying HA rates decreased maximum adsorption capacity, increased P binding energy to soil colloids and did not alter PMBC of Entisol. Available P contents in Oxisol increased with HA rates, but it did not change in Entisol. Choosing the right HA rate can decrease PMBC up to 40% and increase the Oxisol P availability by 17%. Application of MgCO3 instead of CaCO3 decreased P adsorption in both soils. Thus, a positive correlation between Ca2+ content and PMBC was verified. Optimum rate of HA and the preponderance of Mg2+ instead of Ca2+ in soil volume fertilized with P are effective practices to reduce adsorption and increase P availability, especially in clayey Oxisol.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542018000100007
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| Editor: |
Editora da Universidade Federal de Lavras
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| Relação: |
10.1590/1413-70542018421014518
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| Formato: |
text/html
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| Fonte: |
Ciência e Agrotecnologia v.42 n.1 2018
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| Direitos: |
info:eu-repo/semantics/openAccess
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