Balanço de radiação de renques de cafeeiros
Agriambi
Balanço de radiação de renques de cafeeiros
Autor Correspondente: Luiz R Angelocci | [email protected]
Palavras-chave: correlação, instrumentação, radiação solar, saldo de radiação
Resumos Cadastrados
Resumo Português:
The radiation balance of hedgerows is an important variable in studies of mass and energy exchanges between parcial
ground cover crops and the atmosphere. This paper describes a device with eight net radiometers encompassing the
plants of a hedgerow. The radiometers were moved along a length of hedgerow, in a continuous and reversible movement.
The canopy net radiation in this length (Rnc) was found by integration of the measurements over the notional
cylinder formed. The device showed good performance and provided reliable measurements of Rnc of coffee hedgerows,
showing itselfto be an useful technique of measurement in field conditions. Good correlations between Rnc and global
solar radiation, turfgrass and coffee crop net radiation were found in 15-min, daytime and 24-hr periods, allowing the
possibility of estimating Rnc from these simple measurements. Beer’s law was also used to have an independent estimation
of Rnc. A good agreement was found between values of Rnc estimated by this law of attenuation and those integrated
by the device in periods of 15 min, with overestimation of 10%, whereas for values integrated over daytime periods
the agreement was not satisfactory.
Resumo Inglês:
The radiation balance of hedgerows is an important variable in studies of mass and energy exchanges between parcial
ground cover crops and the atmosphere. This paper describes a device with eight net radiometers encompassing the
plants of a hedgerow. The radiometers were moved along a length of hedgerow, in a continuous and reversible movement.
The canopy net radiation in this length (Rnc) was found by integration of the measurements over the notional
cylinder formed. The device showed good performance and provided reliable measurements of Rnc of coffee hedgerows,
showing itselfto be an useful technique of measurement in field conditions. Good correlations between Rnc and global
solar radiation, turfgrass and coffee crop net radiation were found in 15-min, daytime and 24-hr periods, allowing the
possibility of estimating Rnc from these simple measurements. Beer’s law was also used to have an independent estimation
of Rnc. A good agreement was found between values of Rnc estimated by this law of attenuation and those integrated
by the device in periods of 15 min, with overestimation of 10%, whereas for values integrated over daytime periods
the agreement was not satisfactory.
