Solar radiation use efficiency by soybean under field conditions in the Amazon region


Autoria(s): Souza,Paulo Jorge de Oliveira Ponte de; Ribeiro,Aristides; Rocha,Edson José Paulino da; Farias,José Renato Bouça; Loureiro,Renata Silva; Bispo,Carlos Capela; Sampaio,Leila
Data(s)

01/10/2009

Resumo

The objective of this work was to evaluate the efficiency of soybean (Glycine max) in intercepting and using solar radiation under natural field conditions, in the Amazon region, Brazil. The meteorological data and the values of soybean growth and leaf area were obtained from an agrometeorological experiment carried out in Paragominas, Pará state, during 2007 and 2008. The radiation use efficiency (RUE) was obtained from the ratio between the above-ground biomass production and the intercepted photosynthetically active radiation (PAR) accumulated to 99 and 95 days after sowing, in 2007 and 2008, respectively. Climatic conditions during the experiment were very distinct, with reduction in rainfall in 2007, which began during the soybean mid-cycle, due to the El Niño phenomenon. An important reduction in the leaf area index and biomass production was observed during 2007. Under natural field conditions in the Amazon region, the values of RUE were 1.46 and 1.99 g MJ-1 PAR in the 2007 and 2008 experiments, respectively. The probable reason for the differences found between these years might be associated to the water restriction in 2007 coupled with the higher air temperature and vapor pressure deficit, and also to the increase in the fraction of diffuse radiation that reached the land surface in 2008.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009001000001

Idioma(s)

en

Publicador

Embrapa Informação Tecnológica

Pesquisa Agropecuária Brasileira

Fonte

Pesquisa Agropecuária Brasileira v.44 n.10 2009

Palavras-Chave #Glycine max #Amazon region #leaf area index #radiation interception
Tipo

journal article