Data/hora: 15/06/2024 15:28:11

Biblioteca(s): | Embrapa Agricultura Digital.
Data corrente: | 16/02/2009
Data da última atualização: | 15/01/2020
Autoria: | RIGHI, E. Z.; ANGELOCCI, L. R.; MARIN, F. R.
Afiliação: | EVANDRO ZANINI RIGHI, PUC-PR; LUIZ ROBERTO ANGELOCCI, Esalq/USP; FABIO RICARDO MARIN, CNPTIA.
Título: | Energy balance of a young drip-irrigated coffee crop in southeast Brazil: an analysis of errors and reliability of measurements by the Bowen ratio method.
Ano de publicação: | 2007
Fonte/Imprenta: | Revista Brasileira de Agrometeorologia, Piracicaba, v. 15, n. 3, p. 267-279, 2007.
Idioma: | Inglês
Conteúdo: | The energy balance of a young (one to two year-old), drip irrigated coffee crop in hedgerows configuration was determined using the energy balance-Bowen ratio (EBBR) method, during two periods in the wet season [October?Dezember/2002 (P1) and February?March/2003 (P2)] and two in the dry season [May?July/2003 (P3) and August?September/2003 (P4)], in Piracicaba, São Paulo State, Brazil. An analysis of errors affecting the estimates of latent and sensible heat fluxes was performed. Emphasis was given on determining the reliability of the assumption that Kh=Kw in the EBBR method, in view of the possibility of occurrence of sensible heat advection (regional and or within-row) and on the effect of errors of measurements of the air temperature and vapor pressure through the use of thermocouple psychrometers. The psychrometric errors had a more prevalent effect in the dry periods when the humidity gradients were lower than during the humid periods, leading to a larger discarding of measurement during P3 and P4. In the wet periods, it was deduced that the assumption of Kh=Kw did not introduce a large effect on the estimates of the heat fluxes, but during the dry periods this similarity could not be assumed as a function of advective fluxes. The soil surface water conditions were the main factor that determined the energy partitioning. The latent heat flux represented more than 80% of the available energy (Rn?G) in the wet season, decreasing to 78% in P3 and 64% in P4, the dry periods. However, values obtained during P4 were affected by problems on management of the coffee crop. Weeds growing in the inter-rows affected the energy partitioning mostly during periods with low rainfall. The effect of coffee growth and the weeds on the latent heat flux was masked by the soil humidity inside each studied period. In the early dry period, the effect of inter-row weeds on the latent heat flux was important, because they could have extracted water from deep depths in the soil.
Palavras-Chave: | Advecção; Calor sensível; Erros de medidas; Fluxo de energia latente; Psicrometria; Psychrometry.
Thesagro: | Balanço de energia; Café; Clima; Irrigação.
Thesaurus Nal: | advection.
Categoria do assunto: | X Pesquisa, Tecnologia e Engenharia
Registro original: | Embrapa Agricultura Digital (CNPTIA)

Exemplares:

CNPTIA - (12496-1) - UPC - AP - PP -  -  - 2009.00026 - DES
CNPTIA - (12496-2) - UPC - AP - DD -  -  -  - DIS