Necessidade hídrica da cana-de-açúcar no Noroeste Paulista
Carregando...
Data
2018-03-02
Autores
Arroyo Avilez, Alberto Mario
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A cultura da cana de açúcar tem grande importância econômica e é uma das principais culturas na região Noroeste Paulista. Para máximas produtividades e eficiência do uso da água cabe ao produtor desta cultura compreender a necessidade hídrica, quantificando o volume de água necessário durante o seu ciclo de desenvolvimento e, para tanto, o conhecimento da evapotranspiração da referência (ETo) e dos coeficientes de cultura (Kc) ao longo do ciclo, os quais são fundamentais como estratégia de manejo quando a opção de controle é baseada via atmosfera. Neste trabalho o objetivo foi determinar a necessidade hídrica total e a média diária da cultura da cana-de-açúcar no Noroeste Paulista, realizar o balanço hídrico e manejo da irrigação usando um sistema de irrigação por gotejamento e estimar a relação ETa/ETo usando o modelo SAFER (Simple Algorithm for Retrieving Evapotranspiration). A necessidade hídrica total variou entre 1000 mm/safra e 1600 mm/safra dependendo da duração do ciclo da cultura, a necessidade diária teve uma variação entre os 3,6 mm dia-1 e 4,2 mm dia-1, dependente do valor da ETo. Observou-se que o sistema de irrigação não consegue aplicar a lâmina diária necessária para a cultura, em média aos 4,1 mm dia-1. O manejo de irrigação recomendado foi de um turno de rega fixo de 5 dias. No cálculo da relação ETa/ETo, o comportamento da curva formada pelos valores determinados mostrou coerência com as curvas encontradas na literatura, entretanto os valores encontrados foram menores do que aqueles recomendados, mas ainda assim favoráveis para o estudo da necessidade de água da cana-de-açúcar no Noroeste Paulista, devendo-se continuar com estudos que calibrem o algoritmo SAFER para obtenção de melhores resultados.
The culture of sugarcane has great economic importance and is one of the main crops in the Northwest region of São Paulo state. For maximum productivity and water use efficiency, it is the responsibility of the grower of this crop to understand the water requirement, quantifying the volume of water required during its development cycle and, therefore, knowledge of reference evapotranspiration (ETo) and crop coefficients (Kc) during the cycle which are fundamental as a management strategy when the control option is based via atmosphere. In this work the objective was to determine the daily and total daily water requirement of the sugarcane crop in Northwest of the São Paulo state, to perform the water balance and irrigation management using a drip irrigation system and estimate the ETa/ETo ratio using the SAFER (Simple Algorithm for Retrieving Evapotranspiration) model, the total water requirement ranged from 1000 mm /crop to 1600 mm /crop depending on the duration of the culture cycle, the daily requirement had a variation between 3.6 mm /day and 4.2 mm /day, depending of the value of ETo. It was observed that the irrigation system can’t apply the daily blade needed by the crop on average to 4.1 mm /day. The irrigation management recomm ended was a fixed irrigation shift of 5 days. In the calculation of the ETa/ETo ratio, the behavior of the curve formed by the determined values showed coherence with the curves found in the literature, however the values found were lower than those recomm ended but still favorable for the study of the needed of sugarcane water in the Northwest of São Paulo state region, and it is necessary to continue studies that calibrate the SAFER algorithm to obtain better results.
The culture of sugarcane has great economic importance and is one of the main crops in the Northwest region of São Paulo state. For maximum productivity and water use efficiency, it is the responsibility of the grower of this crop to understand the water requirement, quantifying the volume of water required during its development cycle and, therefore, knowledge of reference evapotranspiration (ETo) and crop coefficients (Kc) during the cycle which are fundamental as a management strategy when the control option is based via atmosphere. In this work the objective was to determine the daily and total daily water requirement of the sugarcane crop in Northwest of the São Paulo state, to perform the water balance and irrigation management using a drip irrigation system and estimate the ETa/ETo ratio using the SAFER (Simple Algorithm for Retrieving Evapotranspiration) model, the total water requirement ranged from 1000 mm /crop to 1600 mm /crop depending on the duration of the culture cycle, the daily requirement had a variation between 3.6 mm /day and 4.2 mm /day, depending of the value of ETo. It was observed that the irrigation system can’t apply the daily blade needed by the crop on average to 4.1 mm /day. The irrigation management recomm ended was a fixed irrigation shift of 5 days. In the calculation of the ETa/ETo ratio, the behavior of the curve formed by the determined values showed coherence with the curves found in the literature, however the values found were lower than those recomm ended but still favorable for the study of the needed of sugarcane water in the Northwest of São Paulo state region, and it is necessary to continue studies that calibrate the SAFER algorithm to obtain better results.
Descrição
Palavras-chave
Balanço hídrico, Evapotranspiração., Manejo da irrigação, Necessidade hídrica, Water balance, Evapotranspiration, Irrigation management, Water need