Ajuste E Aplicação Do Irrigâmetro No Manejo Da Água De Irrigação

Abstract

This study aimed to determine heights of water levels in the evaporimeter of the Irrigameter to directly obtain the evapotranspiration of the crop (ETc) in several stages of its growth. Moreover, evaluate the performance of the Irrigameter at managing irrigation in the bean cowpea crop. The study was conducted in the Campus of the State University of

Performance of different methods to estimate reference evapotranspiration in Cruz Alta - RS

“…Disagreeing with the present study, for the methods of Priestley-Taylor and Hargreaves-Samani, Guedes Filho et al (2011) and Silva et al (2012) observed a tendency of ETo underestimation in daily data for the city of Areia -PB and for the northern region of Recife -PE, respectively. On the other hand, Tagliaferre et al (2010) observed, for Eunápolia -BA, a behavior similar to that observed in this study, where the Hargreaves-Samani method showed a tendency of 23% overestimation of ETo data. Vallory et al (2016) also observed a tendency of overestimation of ETo data for the state of Rio de Janeiro, using the PriestleyTaylor and Hargreaves-Samani methods.…”

“…Tagliaferre et al (2010), in Eunápolis -BA and Uberlândia -MG, and Sanches et al (2015), in the northern region of Brazil, also found the Priestley-Taylor method to be of better performance among other methods used.…”

“…One of the main parameters used to determine the water requirement of crops is evapotranspiration (Morais et al, 2015). Its correct obtention is of paramount importance for a proper irrigation management, since it represents the amount of soil water to be replenished for the plants, according to the climatic and soil water conditions in the region (Tagliaferre et al, 2010) The reference evapotranspiration (ETo) can be obtained directly -through the estimation of the soil water balance, using lysimeters -, or indirectly, through evaporimeters or through the use of physical-mathematical models of estimation (Alves Sobrinho et al, 2011;Carvalho et al, 2015;Tanaka et al, 2016). Among the existing models, the Penman-Monteith method, considered as standard by FAO (Allen et al, 1998), besides obtaining a better precision in the estimates, is the model that best represents the physical and physiological factors involved in ETo (Carvalho et al, 2015).…”

“…For the correct use of simplified models in substitution to the standard method of PenmanMonteith, local and regional calibrations, in addition to statistical model performance evaluations, are important for evaluating errors in ETo estimates and guiding the choice of methods that best suit the availability of local meteorological data and the level of accuracy demanded (Tagliaferre et al, 2010;Souza et al, 2011;Carvalho et al, 2015).…”

Métodos para análise de concordância: estudo de simulação e aplicação a dados de evapotranspiração

“…Figura 2 -Irrigâmetro instalado. No detalhe se observam a indicação da lâmina evapotranspirada (10,0 mm), o tempo de irrigação (3:00 h) e o momento de irrigar (cor amarela) 1 Disponível em: <http://irrigacerto.com.br/> Acesso em: out., 2015. De acordo com os resultados obtidos por Oliveira et al (2007a), Oliveira et al (2007b), Tagliaferre et al (2012) e Tagliaferre et al (2014), o Irrigâmetro pode ser usado para estimar a evapotranspiração de qualquer cultura, em qualquer estádio de desenvolvimento, para um valor de Kc (coeciente de cultura) desejado. Sendo assim, o uso do Irrigâmetro torna-se uma alternativa viável por ser de custo mais baixo que o tanque Classe "A" o lisímetro de pesagem e a estação meteorológica automática e, principalmente, por ser de fácil operação (OLIVEIRA et al, 2008a), a qual consiste simplesmente em abrir e fechar válvulas nele existentes, obedecendo a uma sequência predenida, além de apresentar simples montagem e desmontagem, o que facilita o transporte e a sua instalação no campo (GIOVANELLI, 2012).…”