Data/hora: 03/06/2024 09:28:15

Provedor de dados: | 65
País: | Brazil
Título: | Gas chromatography and photoacoustic spectroscopy for the assessment of soil greenhouse gases emissions
Autores: | Nicoloso,Rodrigo da Silveira; Bayer,Cimélio; Denega,Genuir Luis; Oliveira,Paulo Armando Victória de; Higarashi,Martha Mayumi; Corrêa,Juliano Corulli; Lopes,Letícia dos Santos.
Data: | 2013-02-01
Ano: | 2013
Palavras-chave: | No-tillage; Conventional tillage; Cover crops; INNOVA 1412.
Resumo: | Assessments of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions are critical for determination of the agricultural practices' potential to mitigate global warming. This study evaluated the photoacoustic spectroscopy (PAS) for the assessment of soil greenhouse gases (GHG) fluxes in comparison to the standard gas chromatography (GC) method. Two long-term experiments with different tillage and cropping systems over a Paleudult were evaluated using static chambers. PAS measurements of CO2 and N2O concentrations showed good relationship and linearity (R2=0.98 and 0.94, respectively) with GC results. However, CH4 measurements were significantly affected by air sample moisture which interfered on CH4 detection by PAS. Overestimation of CO2 and N2O concentrations in air samples determined by PAS (14.6 and 18.7%, respectively) were also related to sampling moisture. CO2 and N2O fluxes showed good agreement between methods (R2=0.96 and 0.95, respectively), though PAS overestimated fluxes by 18.6 and 13.6% in relation to GC results, respectively. PAS showed good sensitivity and was able to detect CO2 and N2O fluxes as low as 332mg CO2 m-2 h-1 and 21µg N2O m-2 h-1. PAS analyzer should be detailed calibrated to reduce humidity interference on CO2, CH4 and N2O concentrations measurements avoiding overestimation or erroneous determination of soil GHG fluxes.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782013000200012
Editor: | Universidade Federal de Santa Maria
Relação: | 10.1590/S0103-84782013000200012
Formato: | text/html
Fonte: | Ciência Rural  v.43 n.2 2013
Fonte: | info:eu-repo/semantics/openAccess