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Carvalho,Márcia Thaís de Melo; Madari,Beáta Emoke; Bastiaans,Lammert; Oort,Pepijn Adrianus Johannes van; Leal,Wesley Gabriel de Oliveira; Souza,Diego Mendes de; Santos,Roberto Carlos dos; Matsushige,Iva; Maia,Aline de Holanda Nunes; Heinemann,Alexandre Bryan; Meinke,Holger. |
Abstract The objective of this work was to investigate the impact of the application of wood biochar, combined with N fertilizations, on N2O-N fluxes, nitrogen availability, and water-filled pore space (WFPS) of a clayey Oxisol under rice (wet season) and common bean (dry season) succession. Manual static chambers were used to quantify N2O-N fluxes from soil immediately after a single application of wood biochar (32 Mg ha-1) and after four crop seasons with N applications (90 kg ha-1 N). Soil ammonium (N-NH4+) and nitrate (N-NO3-) availability, as well as WFPS, was measured together with N2O-N fluxes. There was no interaction between biochar and N fertilization regarding N2O-N fluxes in any of the four seasons monitored, although these fluxes were clearly... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cropping systems; Gas fluxes; Greenhouse gases; Nitrate and ammonium; Soil amendment; Soil porosity. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901203 |
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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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Sato,Juliana Hiromi; Figueiredo,Cícero Célio de; Marchão,Robélio Leandro; Madari,Beáta Emöke; Benedito,Luiz Eduardo Celino; Busato,Jader Galba; Souza,Diego Mendes de. |
Several methods exist for determining soil organic carbon, and each one has its own advantages and limitations. Consequently, a comparison of the experimental results obtained when these methods are employed is hampered, causing problems in the comparison of carbon stocks in soils. This study aimed at evaluating the analytical procedures used in the determination of carbon and their relationships with soil mineralogy and texture. Wet combustion methods, including Walkley-Black, Mebius and Colorimetric determination as well as dry combustion methods, such as Elemental and Gravimetric Analysis were used. Quantitative textural and mineralogical (kaolinite, goethite and gibbsite) analyses were also carried out. The wet digestion methods underestimated the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil organic matter; Wet combustion; Dry combustion. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162014000400007 |
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