Please use this identifier to cite or link to this item:
|Title: ||Measuring and Modelling Transpiration Versus Evapotranspiration of a Tomato Crop Grown on Soil in a Mediterranean Greenhouse|
|Authors: ||Baptista, F.J.|
|Editors: ||van Straten et al, G.|
|Issue Date: ||2005|
|Citation: ||BAPTISTA FJ, BAILEY BJ AND MENESES JF. 2005. Measuring and modelling transpiration versus evapotranspiration of a tomato crop grown on soil in a Mediterranean greenhouse. Acta Horticulturae 691:313-319.|
|Abstract: ||The main sources of water vapour in a greenhouse are plant transpiration and
the evaporation of water from soil (evapotranspiration). These processes are influ-
enced by environmental factors such as solar radiation and water vapour pressure
deficit, as shown by the Penman-Monteith equation. Most previous studies have been
conducted in Northern countries and with soiless crops, which means that they only
refer to transpiration. In Mediterranean greenhouses many crops are still grown on
soil, so evaporation adds another component to the water vapour balance.
The purpose of this study was: 1 – to measure the evapotranspiration (soil and
crop) and transpiration (crop), of a tomato crop grown on a heavy soil using a lysi-
meter; 2 – to develop models as a function of the inside solar radiation and water
vapour pressure deficit; 3 – to validate the models using data from different days and
4 - to compare the models.
Experiments were conducted in a Mediterranean unheated greenhouse
covered with co-extruded PE-EVA-PE film, with a soil grown tomato crop, located in
Lisbon. The orientation was east-west and ventilation was achieved by continuous
apertures located on the side walls over its entire length. Trickle ferti-irrigation tubes
were located between each two rows of plants. Climatic parameters, such as dry and
wet bulb air temperatures, crop and leaf temperatures and solar radiation were
measured and recorded using a data logger. Information on the evolution of the crop
was also recorded.
To compute evapotranspiration and transpiration a lysimeter was used and
data of irrigation, drainage and soil moisture content were recorded. For the evalua-
tion of the transpiration, the lysimeter was covered with a plastic film to prevent
evaporation from the soil.
To develop the models, data were recorded over periods of several days at
different stages of plant development and another set of data from different periods
was used for model validation. Comparison between measured and estimated data
shows good agreement for both models. Differences between transpiration and evapo-
transpiration were very small, which reveals that, under the conditions experienced,
evaporation from the soil can be neglected when trickle ferti-irrigation is used.|
|Appears in Collections:||MED - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica|
ERU - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.