Variabilidade espaço-temporal da temperatura e difusividade térmica do solo de Lagoa Seca-PB

Abstract

O objetivo deste trabalho foi investigar a variabilidade espaço-temporal da temperatura e difusividade térmica do solo de Lagoa Seca-PB. Para alcançar este objetivo foram utilizados sensores de temperatura, programados a operar ininterruptamente ao longo dos ciclos diários, instalados em quatro profundidades distintas do solo. Estes, por sua vez, monitoraram o comportamento térmico do solo durante todo o ano de 2010 e 2011. A fim de estimar a difusividade térmica do solo foram empregados três métodos distintos: método da amplitude, método do arco tangente e método logarítmico. O regime térmico do solo, no que diz respeito às horas e aos meses de ocorrência das máximas e mínimas temperaturas, apresentaram-se bastante semelhantes em ambos os anos. O método do arco tangente, para o caso específico da camada compreendida entre 5 e 50 cm de profundidade, não é adequado para a estimativa da difusividade térmica do solo. Palavras-chave: difusividade térmica, física do solo, regime térmico, temperatura do solo.

Hourly, Daily, and Monthly Soil Temperature Fluctuations in a Drought Tolerant Crop

“…Therefore, the 0.10 m layer for all months showed a soil temperature fluctuation closer to the 0.05 m layer than to the 0.20 m layer. Similar results were found by Belan et al (2013) and Diniz et al (2014), who found that maximum temperatures occurred at different times. The delay from surface to deeper depths showed that the heat wave requires a certain time period to propagate in the soil because of slow heat conduction capacity through the vertical soil profile, as mentioned above.…”

“…In another study developed by Diniz et al (2014) in the state of Paraiba, Brazil, considering depths from 0.05 to 0.15 m, October showed the lowest thermal diffusivity (0.59 × 10 -6 m 2 s -1 ) and June showed the highest (1.11 × 10 -6 m 2 s -1 ) in 2010. According to the authors, June had the greatest rainfall; therefore, the soil pore space was filled with water, providing greater heat conduction capacity.…”

“…The correlation between soil and air temperatures was studied by Azevedo and Galvani (2003), Carvalho et al (2009), Belan et al (2013), and Awe et al (2015), while thermal diffusivity in soil was evaluated by Amaro Filho et al (2008), Diniz et al (2014), Soares et al (2014), and Oliveira et al (2015). Several studies conducted in different soil management systems obtained a significant and inverse relationship between soil temperature and cover crop with residual or cultural biomass (Dourado-Neto et al, 1999;Silva et al, 2006).…”

“…Several studies have been performed to evaluate daily (Kunz et al, 2002;Oliveira et al, 2010;Belan et al, 2013;Diniz et al, 2013aDiniz et al, , 2014, monthly (Diniz et al, 2013a), and yearly (Carneiro et al, 2014) soil temperature fluctuations. The correlation between soil and air temperatures was studied by Azevedo and Galvani (2003), Carvalho et al (2009), Belan et al (2013), and Awe et al (2015), while thermal diffusivity in soil was evaluated by Amaro Filho et al (2008), Diniz et al (2014), Soares et al (2014), and Oliveira et al (2015).…”