Diurnal variation of methane emission from a paddy field in Brazilian Southeast/Variacao diurna da emissao de metano em arroz irrigado no Sudeste do Brasil

This study aimed to investigate the diurnal variation of methane (C[H.sub.4]) emission in a flooded-irrigated rice field at different stages of the plant development under tropical climate in three growing seasons, in order to determine the most appropriate time for gas sampling in the Brazilian Sou...

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Bibliographic Details
Published in:Ciência rural 2018-04, Vol.48 (4)
Main Authors: de Lima, Magda Aparecida, Pazianotto, Ricardo Antonio Almeida, Villela, Omar Vieira, Paraiba, Lourival Costa
Format: Article
Language:Spanish
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Summary:This study aimed to investigate the diurnal variation of methane (C[H.sub.4]) emission in a flooded-irrigated rice field at different stages of the plant development under tropical climate in three growing seasons, in order to determine the most appropriate time for gas sampling in the Brazilian Southeast region. It aimed also to verify correlations between C[H.sub.4] flux and air, water and soil temperatures, and solar radiation. The C[H.sub.4] emissions were measured every 3-hour interval on specific days in different development stages of the flooded rice in the Experiment Station of the Agencia Paulista de Tecnologia dos Agronegocios (APTA), Polo Regional Vale do Paraiba, at Pindamonhangaba, State of Sao Paulo (22[degrees]55 'S, 45[degrees]30 ' W), Brazil. Different C[H.sub.4] emission rates were observed among the plant growth stages and also among the growing seasons. The C[H.sub.4] emission showed high correlation with the soil temperature at 2cm depth. At this depth, the C[H.sub.4] emission activation energy in response to soil temperature was higher in the stage R2. Emission peaks were observed at afternoon, while lower fluxes were recorded at the early morning. The most appropriate local time for gas sampling was estimated at 12:11:15a.m. [+ or -] 01:14:16 and 09:05:49p.m. [+ or -] 01:29:04. Key words: flooded rice, methane flux, plant development stage, activation energy. Este estudo teve como objetivo investigar a variacao diurna de emissoes de metano (CH) em uma lavoura de arroz irrigado por inundacao em diferentes estagios de desenvolvimento de plantas de arroz irrigado, sob clima tropical, em tres estacoes de crescimento, para determinar o periodo de tempo mais apropriado a amostragem de gas na regiao Sudeste do Brasil. O trabalho objetivou tambem verificar correlacoes entre o fluxo de C[H.sub.4] e as temperaturas do ar, da agua e do solo e a radiacao solar. As emissoes diurnas de C[H.sub.4] foram medidas a cada intervalo de tres (3) horas em dias especificos em diferentes estagios de desenvolvimento da planta de arroz inundado na Estacao Experimental da Agencia Paulista de Tecnologia dos Agronegocios (APTA), Polo Regional Vale do Paraiba, em Pindamonhangaba, Estado de Sao Paulo (22[grados]55' S, 45[grados]30' W), Brasil. Diferentes taxas de emissao foram observadas entre os estagios de desenvolvimento da planta avaliados e tambem entre as estacoes de cultivo. A emissao de C[H.sub.4] mostrou alta correlacao com a temperatura do solo a 2cm de
ISSN:0103-8478
1678-4596
DOI:10.1590/0103-8478cr20170054