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| Alencar,Ernandes R. de; Faroni,Lêda R. D.; Martins,Marcio A.; Costa,André R. da; Cecon,Paulo R.. |
| This study was conducted to evaluate the decomposition kinetics of gaseous ozone in peanut grains. This evaluation was made with 1-kg peanut samples, moisture contents being 7.1 and 10.5% wet basis (w.b.), placed in 3-liter glass containers. The peanut grains were ozonated at the concentration of 450 µg L-1, at 25 and 35 ºC, with gas flow rates of 1.0 and 3.0 L min-1. Time of saturation was determined by quantifying the residual concentration of ozone after the gas passed through the grains to constant mass. The decomposition kinetics of ozone was evaluated after the grain mass was ozone-saturated. For the peanut grains whose moisture content was 7.1% (w.b.), at 25 and 35ºC and with flow rates of 1.0 and 3.0 L min-1, the values obtained for time of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Concentration of saturation; Time of saturation; Half-life. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162011000500011 |
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| Trezzi,M.M.; Marchesan,E.D.; Vidal,R.A.; Xavier,E.; Dick,D.P.. |
| The intensive use of pesticides have contaminated the soil and groundwater. The application of herbicides as controlled release formulations may reduce the environmental damage related to their use because it may optimize the efficiency of the active ingredient and reducing thus the recommended dose. The objective of this study was to evaluate the persistence of the herbicide atrazine applied as commercial formulation (COM) and as controlled release formulation (xerogel - XER) in Oxisol. The experimental design used was split-plot randomized-blocks with four replications, in a (2 x 6) + 1 arrangement. The two formulations (COM and XER) were assigned to main plots and different atrazine concentrations (0, 3.200, 3.600, 4.200, 5.400 and 8.000 g atrazine... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Residual herbicides; Controlled release; Half-life. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000300018 |
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| Briedis,Clever; Sá,João Carlos de Moraes; De-Carli,Roberto Simão; Antunes,Erielton Aparecido Pupo; Simon,Lucas; Romko,Marielle Leticia; Elias,Lucio Schenekenberg; Ferreira,Ademir de Oliveira. |
| In soils under no-tillage (NT), the continuous crop residue input to the surface layer leads to carbon (C) accumulation. This study evaluated a soil under NT in Ponta Grossa (State of Paraná, Brazil) for: 1) the decomposition of black oat (Avena strigosa Schreb.) residues, 2) relation of the biomass decomposition effect with the soil organic carbon (SOC) content, the particulate organic carbon (POC) content, and the soil carbon stratification ratio (SR) of an Inceptisol. The assessments were based on seven samplings (t0 to t6) in a period of 160 days of three transects with six sampling points each. The oat dry biomass was 5.02 Mg ha-1 at t0, however, after 160 days, only 17.8 % of the initial dry biomass was left on the soil surface. The SOC in the 0-5 cm... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Black oat; Carbon sequestration; Dry matter decomposition; Half-life. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000500012 |
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| Teixeira,Renato Alves; Soares,Tatiana Gazel; Fernandes,Antonio Rodrigues; Braz,Anderson Martins de Souza. |
| Studies to select one or more species of coverage plants adapted to Amazonian soil and climate conditions of the Amazon are a promising strategy for the improvement of environmental quality, establishing no-till agricultural systems, and thereby reducing the impacts of monoculture farming. The aim of this study was to assess the persistence time, half-life time, macronutrient content and accumulation, and C:N ratio of straw coverage in a Ultisol in northeastern Pará. Experimental design was randomized blocks with five treatments and five replicates. Plants were harvested after 105 days, growth and biomass production was quantified. After 84 days, soil coverage was 97, 85, 52, 50, and 15% for signalgrass (Brachiaria brizantha) (syn. Urochloa), dense... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Half-life; Persistence of plant biomass; Recycling nutrients; C / N ratio. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672014000400002 |
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| Martinez,Camila O.; Silva,Celia Maria M. S.; Fay,Elisabeth F.; Abakerli,Rosangela B.; Maia,Aline H. N.; Durrant,Lucia R.. |
| Sulfentrazone is amongst the most widely used herbicides for treating the main crops in the State of São Paulo, Brazil, but few studies are available on the biotransformation of this compound in Brazilian soils. Soil samples of Rhodic Hapludox soil were supplemented with sulfentrazone (0.7 µg active ingredient (a.i.) g-1 soil) and maintained at 27ºC. The soil moisture content was corrected to 30, 70 or 100 % water holding capacity (WHC) and maintained constant until the end of the experimental period. Herbicide-free soil samples were used as controls. Another experiment was carried out using soil samples maintained at a constant moisture content of 70% WHC, supplemented or otherwise with the herbicide, and submitted to different temperatures of 15, 30 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Degradation; Microorganisms; Half-life. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000100030 |
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