Dinâmica de transpiração da oliveira em diferentes regimes hídricos
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2022-06-15
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A oliveira (Olea europaea L.) é uma das culturas com maior dispersão por todo o mundo. Em Portugal, como as condições edafo-climáticas são ótimas para o desenvolvimento desta cultura, a olivicultura apresenta-se como uma atividade de grande importância socioeconómica.
Com as alterações climáticas que se têm verificado nos últimos anos, cada vez mais os olivais Transmontanos, à semelhança dos olivais do resto do País, são regados com o objetivo de reduzir os efeitos negativos que advém dessas alterações e, em simultâneo, garantir a produtividade do olival. Por outro lado, a escassez de água também é um problema muito atual, que põe em causa o uso de água na agricultura.
Deste modo surgiram os objetivos gerais deste estudo: avaliar diferentes estratégias de rega: i) situação em conforto hídrico; ii) situação de rega deficitária contínua e iii) situação de rega deficitária controlada, tentando otimizar a quantidade de água a aplicar, tendo em conta as necessidades hídricas das plantas.
Para perceber a dinâmica do uso da água necessária avaliaram-se diferentes indicadores do estado hídrico da oliveira (potencial hídrico, condutância estomática e teor relativo de água nas folhas) e monitorizou-se o fluxo de seiva no tronco com o objetivo de estudar a dinâmica da transpiração.
Neste estudo, concluiu-se que o método de compensação do impulso de calor parece ser um método útil, fácil de usar e com custos económicos mais baixos do que outros utilizados.
The olive tree (Olea europaea L.) is one of the crops that is widespread around the world. In Portugal, as the soil and climatic conditions are excellent for the development of this crop, the production of olive trees presents itself as an activity of great socioeconomic importance. With the climate changes that has occurred in recent years, irrigation of olive orchards in the region of Trás-os-Montes has been increased, like in other regions of Portugal, with the aim to mitigate the negative effects that arise from these changes and, simultaneously, guaranteeing the productivity of the olive orchards. On the other hand, water scarcity is also a very current problem, thus is crucial the rational use of water in agriculture. In this way, the general objectives of this study emerged: to evaluate different irrigation strategies: i) situation in water comfort; ii) situation in susteained deficit irrigation and iii) situation in regulated deficit irrigation, trying to optimize the amount of water to be applied, taking into account the water needs of plants. To understand water relations in the continuum soil plant atmosphere, different indicators of plant water status (water potential, stomatal conductance and relative water content in the leaves) were evaluated and the sap flow in the trunk was monitored in order to study the dynamics of transpiration. In this study it was concluded that the heat impulse method seems to be a useful method, easy to use and with lower economic costs that others used.
The olive tree (Olea europaea L.) is one of the crops that is widespread around the world. In Portugal, as the soil and climatic conditions are excellent for the development of this crop, the production of olive trees presents itself as an activity of great socioeconomic importance. With the climate changes that has occurred in recent years, irrigation of olive orchards in the region of Trás-os-Montes has been increased, like in other regions of Portugal, with the aim to mitigate the negative effects that arise from these changes and, simultaneously, guaranteeing the productivity of the olive orchards. On the other hand, water scarcity is also a very current problem, thus is crucial the rational use of water in agriculture. In this way, the general objectives of this study emerged: to evaluate different irrigation strategies: i) situation in water comfort; ii) situation in susteained deficit irrigation and iii) situation in regulated deficit irrigation, trying to optimize the amount of water to be applied, taking into account the water needs of plants. To understand water relations in the continuum soil plant atmosphere, different indicators of plant water status (water potential, stomatal conductance and relative water content in the leaves) were evaluated and the sap flow in the trunk was monitored in order to study the dynamics of transpiration. In this study it was concluded that the heat impulse method seems to be a useful method, easy to use and with lower economic costs that others used.
Descrição
Dissertação de Mestrado em Engenharia Agronómica
Palavras-chave
Olival , Rega deficitária