Data/hora: 12/06/2024 12:21:00

Provedor de dados: | Scientia Agricola
País: | Brazil
Título: | Calibrated heat-pulse method for the assessment of maize water uptake
Autores: | Santos,Antonio Odair; Bergamaschi,Homero; Rosa,Luiz Mauro G.; Bergonci,João Ito.
Data: | 2000-03-01
Ano: | 2000
Palavras-chave: | Sap flow; Transpiration; Heat-pulse.
Resumo: | Plant water requirements are important aspects of crop production to be determined in the field, in order to judiciously manage crop water usage. Water uptake by field grown maize (Zea mays L.), under well-watered conditions was verified with the heat-pulse system. The temperature difference between two radially inserted thermocouples, one 9 mm above and the other 4 mm below a heater piercing the maize stem, was measured every 0.3 seconds following emission of a heat-pulse. Comparisons of the heat-pulse system outputs, lysimetric measurement and transpiration model estimates were monitored on an hourly and daily basis. At normal and low atmospheric demand daily and hourly values of heat-pulse outputs and lysimetric measurement showed good agreement. Hourly agreement of a modified Penman-Monteith energy balance equation estimate and heat-pulse outputs showed accordance between measurement of sap flow and the plant water-loss theory. Study of the relationship between maize canopy water loss rate and heat velocity in the stem showed that these two parameters were proportional and a calibration factor of 1.51 for full soil foliage coverage was verified.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162000000100006
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/S0103-90162000000100006
Formato: | text/html
Fonte: | Scientia Agricola  v.57 n.1 2000
Fonte: | info:eu-repo/semantics/openAccess