Necessidades de água e estratégias de rega de campos de golfe | Water requirements and irrigation strategies for golf courses

Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura - Instituto Superior de Agronomia

The irrigation management of golf courses has recently become of great importance, mainly in water scarcity conditions. This is due to the increase of water demand in urban areas. The choice of the turf grass is essential for the reduction of water consumption. The main focus of this study is the evaluation of the irrigation systems used in a golf course, located at Oeiras, and the assessment of irrigation water requirements and scheduling strategies to obtain a healthy turf grass. Field assessments provided for the evaluation of the sprinkler irrigation systems, and respective uniformity was estimated. Results have shown that three test areas were classified as uniform, and two other were classified as having sufficient uniformity. The soil water content in different locations was observed under various irrigation schedules: a daily irrigation for C3 grass, and four different schedules for C4 grass: irrigation frequencies of 1, 2, 3 and 4 times per week. The equipment used for measurements of the soil water content was the Delta-T Profile Probe (PR1). These observations allowed the calibration and validation of WinISAREG model and the consequent estimation of crop coefficients and soil water depletion fractions for no-stress relative to both grass types. The landscape net irrigation requirements were calculated through soil water balance simulations, adopting the actual irrigation schedules and soil water content. These irrigation requirements were estimated with the combination of reference evapotranspiration (ETO) with the landscape coefficient parameterized from the crop coefficients derived with the WinISAREG model as referred above. It was observed that the visual quality of the turf grass was affected in C4 grasses when the irrigation frequency decreased below 4 irrigations per week, but the quality of the grass for playing was not affected. The visual quality and conditions for playing of C3 grasses were not affected during the study period. This application to a specific golf course may be extended to other areas using modeling; it also may be concluded that the adopted model can support the decision making on turf grass irrigation for gulf courses when water use has to be improved.-----------------------------------A gestão da rega dos campos de golfe tem-se tornado nos últimos anos de importância vital em especial quando em anos de carência hídrica. Essa importância devese ao aumento da competição pela procura de água no espaço urbano. Assim, os objectivos do presente estudo são a avaliação dos sistemas de rega utilizados num campo de golfe situado na região de Oeiras e avaliar várias estratégias de rega com vista à obtenção de relva de qualidade. Para tal realizou-se trabalho de campo para avaliar os sistemas de rega por aspersão utilizados e foram determinados os índices de uniformidade de distribuição. Observou-se a evolução da água do solo em vários locais correspondendo a um tratamento de rega diária com plantas C3, e quatro tratamentos com plantas C4 com 1, 2, 3 e 4 regas por semana. Estas observações permitiram calibrar e validar o modelo WinISAREG, determinar os coeficientes culturais e a fracção de depleção sem causar stress. As necessidades hídricas do espaço verde foram assim calculadas com base em simulações do balanço hídrico do solo, utilizando os calendários de rega e teores de água do solo observados. Estas necessidades hídricas foram calculadas combinando a evapotranspiração de referência (ETO) com o coeficiente de espaços verdes parametrizado a partir dos coeficientes culturais. Conclui-se que a rega 1 ou 2 vezes por semana é inapropriada para as C4. Esta aplicação a um campo de golfe específico pode ser estendida por modelação e o modelo agora utilizado poderá servir de apoio à gestão.