02861naa a2200277 a 450000100080000000500110000800800410001910000170006024501820007726000090025952019970026865000140226565000240227965000100230365000100231365000160232365300150233965300200235465300210237465300290239565300170242465300170244170000210245870000170247977300870249610245862020-01-15       2007    bl uuuu     u00u1 u    #d1 aRIGHI, E. Z.  aEnergy balance of a young drip-irrigated coffee crop in southeast Brazilban analysis of errors and reliability of measurements by the Bowen ratio method.h[electronic resource]  c2007  aThe 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.  aadvection  aBalanço de energia  aCafé  aClima  aIrrigação  aAdvecção  aCalor sensível  aErros de medidas  aFluxo de energia latente  aPsicrometria  aPsychrometry1 aANGELOCCI, L. R.1 aMARIN, F. R.  tRevista Brasileira de Agrometeorologia, Piracicabagv. 15, n. 3, p. 267-279, 2007.