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Souza,Diego Mendes de; Morais,Pedro Augusto de Oliveira; Matsushige,Ivã; Rosa,Luismar Alves. |
ABSTRACT Soil organic matter (SOM) is important to fertility, since it performs several functions such as cycling, water and nutrient retention and soil aggregation, in addition to being an energy requirement for biological activity. This study proposes new trends to the Embrapa, Walkley-Black, and Mebius methods that allowed the determination of SOM by spectrophotometry, increasing functionality. The mass of 500 mg was reduced to 200 mg, generating a mean of 60 % saving of reagents and a decrease of 91 % in the volume of residue generated for the three methods without compromising accuracy and precision. We were able to optimize conditions for the Mebius method and establish the digestion time of maximum recovery of SOM by factorial design and response... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: SOM; Spectrophotometry; Increase in functionality; Response surface. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100419 |
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Demolinari,Michelle de Sales Moreira; Sousa,Rodrigo Nogueira de; Silva,Ivo Ribeiro da; Teixeira,Rafael da Silva; Neves,Júlio César Lima; Mendes,Gilberto de Oliveira. |
ABSTRACT The amount of harvest residues retained in Eucalyptus plantations strongly influences soil organic matter (SOM), but the efficiency of conversion to SOM may vary according to the type of residue. This study evaluated the recovery of C from Eucalyptus residue components - leaves, bark, branches, roots, and a mix of all residues - in different SOM fractions with or without mineral-N supplementation (200 mg kg-1 of N). Variation in natural 13C abundance was used to trace the destination of residue-derived C in the soil. The C content of the light fraction (LF) and heavy fraction (HF) of SOM increased over a 240-days decomposition period in response to incorporation of Eucalyptus residues in the soil. Bark and leaf residues showed the best results.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: C cycling; N cycling; SOM; Stable isotopes. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100418 |
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