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E Fereres - One of the best experts on this subject based on the ideXlab platform.
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Measurement and estimation of Plastic greenhouse reference evapotranspiration in a Mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, M. R. Granados, J C Lopez, Francisco Orgaz, S. Bonachela, R. Thompson, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ET_o) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ET_o in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ET_o inside a Plastic greenhouse with a perennial grass in Almería, south-eastern Spain. Mean daily measured greenhouse ET_o ranged from values slightly less than 1 mm day^−1 during winter to values of approximately 4 mm day^−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ET_o was reduced by an average of 21.4%. Different methodologies to calculate ET_o were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m^−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ET_o because of their simplicity.
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measurement and estimation of Plastic greenhouse reference evapotranspiration in a mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, R. B. Thompson, M. R. Granados, J C Lopez, Santiago Bonachela, Francisco Orgaz, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ETo) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ETo in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ETo inside a Plastic greenhouse with a perennial grass in Almeria, south-eastern Spain. Mean daily measured greenhouse ETo ranged from values slightly less than 1 mm day−1 during winter to values of approximately 4 mm day−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ETo was reduced by an average of 21.4%. Different methodologies to calculate ETo were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ETo because of their simplicity.
M. Gallardo - One of the best experts on this subject based on the ideXlab platform.
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VegSyst, a simulation model of daily crop growth, nitrogen uptake and evapotranspiration for pepper crops for use in an on-farm decision support system
Irrigation Science, 2013Co-Authors: C. Giménez, M. Gallardo, C. Martínez-gaitán, C. O. Stöckle, R. B. Thompson, M. R. GranadosAbstract:The VegSyst simulation model was developed to assist with N and irrigation management of sweet pepper grown in Plastic Greenhouses in the Mediterranean Basin. The model was developed for use in an on-farm decision support system with the requirement for readily available input data. Dry matter production (DMP), crop N uptake and crop evapotranspiration (ET_c) are simulated on a daily basis. DMP is calculated from daily fraction of intercepted photosynthetically active radiation (PAR), PAR radiation, and radiation-use efficiency. Fraction of intercepted PAR is calculated from relative thermal time. Crop N uptake is calculated as the product of DMP and N content which is described by a power function of DMP. ET_c is the product of daily reference evapotranspiration (ET_o) using an adapted Penman–Monteith equation, and a daily simulated crop coefficient value. The VegSyst model for soil-grown, greenhouse pepper was calibrated in one crop and validated in three different crops. In the validation, the model accurately simulated crop growth, N uptake and ET_c. Relative to measured values, simulated DMP at final harvest was 0.89–1.06, and crop N uptake was 0.97–1.13. Simulated cumulative ET_c for complete crops was 0.95–1.05 of measured values.
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Measurement and estimation of Plastic greenhouse reference evapotranspiration in a Mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, M. R. Granados, J C Lopez, Francisco Orgaz, S. Bonachela, R. Thompson, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ET_o) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ET_o in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ET_o inside a Plastic greenhouse with a perennial grass in Almería, south-eastern Spain. Mean daily measured greenhouse ET_o ranged from values slightly less than 1 mm day^−1 during winter to values of approximately 4 mm day^−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ET_o was reduced by an average of 21.4%. Different methodologies to calculate ET_o were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m^−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ET_o because of their simplicity.
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measurement and estimation of Plastic greenhouse reference evapotranspiration in a mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, R. B. Thompson, M. R. Granados, J C Lopez, Santiago Bonachela, Francisco Orgaz, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ETo) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ETo in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ETo inside a Plastic greenhouse with a perennial grass in Almeria, south-eastern Spain. Mean daily measured greenhouse ETo ranged from values slightly less than 1 mm day−1 during winter to values of approximately 4 mm day−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ETo was reduced by an average of 21.4%. Different methodologies to calculate ETo were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ETo because of their simplicity.
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effects of salinity on fruit yield and quality of tomato grown in soil less culture in Greenhouses in mediterranean climatic conditions
Agricultural Water Management, 2008Co-Authors: J J Magan, M. Gallardo, R. B. Thompson, P LorenzoAbstract:There is increasing pressure to reduce water use and environmental impact associated with open system, soil-less production in simple, Plastic Greenhouses on the Mediterranean coast. This may force the adoption of re-circulation of nutrient solutions. In south-eastern Spain, irrigation water is mostly from aquifers and has moderate levels of salinity. The adoption of re-circulation using moderately saline water requires detailed information of crop response to salinity, in order to optimise management. The effect of salinity on fruit yield, yield components and fruit quality of tomato grown in soil-less culture in Plastic Greenhouses in Mediterranean climate conditions was evaluated. Two spring growing periods (experiments 1 and 2) and one long season, autumn to spring growing period (experiment 3) studies were conducted. Two cultivars, �Daniela� (experiment 1) and �Boludo� (experiments 2 and 3), were used. Seven levels of electrical conductivity (EC) in the nutrient solution were compared in experiment 1 (2.5�8.0 dS m-1) and five levels in experiments 2 and 3 (2.5�8.5 dS m-1). Total and marketable yield decreased linearly with increasing salinity above a threshold EC value (ECt). There were only small effects of climate and cultivar on the ECt value for yield. Average threshold EC values for total and marketable fruit yield were, respectively, 3.2 and 3.3 dS m-1. The linear reductions of total and marketable yield with EC above ECt showed significant differences between experiments, the slope varying from 7.2% (autumn to spring period, �Boludo�) to 9.9% (spring period, �Boludo�) decreases per dS m-1 increase in EC for total yield, and from 8.1% (spring period, �Daniela�) to 11.8% (spring period, �Boludo�) for marketable yield. The decrease of fresh fruit yield with salinity was mostly due to a linear decrease of the fruit weight of 6.1% per dS m-1 from an ECt of 3.0 dS m-1 for marketable fruits. Reduction in fruit number with salinity made a smaller relative contribution to reduced yield. Blossom-end rot (BER) increased with increasing salinity. There was a higher incidence of BER with spring grown crops, and �Boludo� was more sensitive than �Daniela�. Increasing salinity improved various aspects of fruit quality, such as: (i) proportion of �Extra� fruits (high visual quality), (ii) soluble solids content, and (iii) titratable acidity content. However, salinity decreased fruit size, which is a major determinant of price. An economic analysis indicated that the EC threshold value above which the value of fruit production decreased linearly with increasing salinity was 3.3 dS m-1, which was the same as that for marketable yield. In the economic analysis, the value of increased visual fruit quality was offset by reduced yield and smaller fruit size.
M. R. Granados - One of the best experts on this subject based on the ideXlab platform.
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VegSyst, a simulation model of daily crop growth, nitrogen uptake and evapotranspiration for pepper crops for use in an on-farm decision support system
Irrigation Science, 2013Co-Authors: C. Giménez, M. Gallardo, C. Martínez-gaitán, C. O. Stöckle, R. B. Thompson, M. R. GranadosAbstract:The VegSyst simulation model was developed to assist with N and irrigation management of sweet pepper grown in Plastic Greenhouses in the Mediterranean Basin. The model was developed for use in an on-farm decision support system with the requirement for readily available input data. Dry matter production (DMP), crop N uptake and crop evapotranspiration (ET_c) are simulated on a daily basis. DMP is calculated from daily fraction of intercepted photosynthetically active radiation (PAR), PAR radiation, and radiation-use efficiency. Fraction of intercepted PAR is calculated from relative thermal time. Crop N uptake is calculated as the product of DMP and N content which is described by a power function of DMP. ET_c is the product of daily reference evapotranspiration (ET_o) using an adapted Penman–Monteith equation, and a daily simulated crop coefficient value. The VegSyst model for soil-grown, greenhouse pepper was calibrated in one crop and validated in three different crops. In the validation, the model accurately simulated crop growth, N uptake and ET_c. Relative to measured values, simulated DMP at final harvest was 0.89–1.06, and crop N uptake was 0.97–1.13. Simulated cumulative ET_c for complete crops was 0.95–1.05 of measured values.
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Measurement and estimation of Plastic greenhouse reference evapotranspiration in a Mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, M. R. Granados, J C Lopez, Francisco Orgaz, S. Bonachela, R. Thompson, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ET_o) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ET_o in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ET_o inside a Plastic greenhouse with a perennial grass in Almería, south-eastern Spain. Mean daily measured greenhouse ET_o ranged from values slightly less than 1 mm day^−1 during winter to values of approximately 4 mm day^−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ET_o was reduced by an average of 21.4%. Different methodologies to calculate ET_o were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m^−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ET_o because of their simplicity.
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measurement and estimation of Plastic greenhouse reference evapotranspiration in a mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, R. B. Thompson, M. R. Granados, J C Lopez, Santiago Bonachela, Francisco Orgaz, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ETo) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ETo in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ETo inside a Plastic greenhouse with a perennial grass in Almeria, south-eastern Spain. Mean daily measured greenhouse ETo ranged from values slightly less than 1 mm day−1 during winter to values of approximately 4 mm day−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ETo was reduced by an average of 21.4%. Different methodologies to calculate ETo were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ETo because of their simplicity.
Yanxia Zhang - One of the best experts on this subject based on the ideXlab platform.
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atmospheric phthalate pollution in Plastic agricultural Greenhouses in shaanxi province china
Environmental Pollution, 2021Co-Authors: Xinkai Wang, Yanxia Zhang, Biao Huang, Zhikun Chen, Ming Zhong, Weixi Wang, Xiaofei Liu, Ya Nan FanAbstract:Abstract Phthalate pollution in soil and vegetables in Plastic agricultural Greenhouses has attracted wide concern. Investigating airborne phthalates in this environment can improve understanding of air-soil or air-vegetable phthalate migration. However, studies of phthalates in Plastic agricultural greenhouse air are rare. To fill this gap, 25 gas-phase and 23 particle-phase samples were collected from 12 typical Plastic Greenhouses in Shaanxi. 16 types of phthalates were measured by a gas chromatography-mass spectrometry system (GC-MS) to analyse their pollution features and variations. Results showed that in the air of the Plastic Greenhouses, the median concentration of the sum of sixteen type phthalates (∑16 phthalates) was 5305 ng m−3, with 5th-95th value of 1214–9616 ng m−3. Phthalates in gas-phase samples were over 100 times higher than the levels in particle-phase samples. Air phthalate concentrations in the Plastic Greenhouses were higher than those in the control groups (P
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oral intake exposure to phthalates in vegetables produced in Plastic Greenhouses and its health burden in shaanxi province china
Science of The Total Environment, 2019Co-Authors: Yanxia Zhang, Biao Huang, Zhikun Chen, Ming Zhong, Clive E Sabel, Marianne Thomsen, Xiangyun Gao, Puyang FengAbstract:Abstract Phthalate exposure from Vegetables grown in Plastic Greenhouses (VPGs) represents an important source of total daily phthalate exposure in China. However, quantified health risks of phthalates attributable to VPG intake have not been documented. To fill this gap, this study estimates phthalate exposure from VPG intake in western China and calculates the first assessment of the disease burden associated with phthalate exposure from VPG intake in China based on a simple steady-state exposure model and a linear dose-response function between human bio-monitoring phthalates and Type 2 Diabetes (T2D) prevalence. What we present in this paper is a problem identification and screening level risk assessment. We chose Shaanxi province as the research field site due to its large contribution to the total vegetable yield and consumption in western China. Phthalate concentration in VPG samples, phthalate exposure levels from VPG intake, and the T2D burden caused by phthalate attributable to VPG intake for adults were measured or calculated. Di-2-ethylhexyl phthalate (DEHP) was found to represent over 55% of the total phthalate concentration in VPGs, followed by di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP). Phthalate exposure from VPG intake for urban adults was higher than the level for rural adults. The share of DEHP exposure from VPG intake to urinary total DEHP metabolites were nearly 8% and 15%, and the share of DnBP exposure caused by VPG intake to total daily DnBP metabolites were nearly 4% and 7%, for rural and urban adult populations in Shaanxi, respectively. The adult population with T2D attributable to phthalate exposure from VPG intake was 2561, nearly 6.4% to the T2D burden attributable to total phthalate exposure, and 0.4% to the total adult population with T2D in Shaanxi. The authors recommend policy interventions to protect populations from future risk of phthalate exposure.
M D Fernandez - One of the best experts on this subject based on the ideXlab platform.
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Measurement and estimation of Plastic greenhouse reference evapotranspiration in a Mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, M. R. Granados, J C Lopez, Francisco Orgaz, S. Bonachela, R. Thompson, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ET_o) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ET_o in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ET_o inside a Plastic greenhouse with a perennial grass in Almería, south-eastern Spain. Mean daily measured greenhouse ET_o ranged from values slightly less than 1 mm day^−1 during winter to values of approximately 4 mm day^−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ET_o was reduced by an average of 21.4%. Different methodologies to calculate ET_o were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m^−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ET_o because of their simplicity.
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measurement and estimation of Plastic greenhouse reference evapotranspiration in a mediterranean climate
Irrigation Science, 2010Co-Authors: M D Fernandez, M. Gallardo, R. B. Thompson, M. R. Granados, J C Lopez, Santiago Bonachela, Francisco Orgaz, E FereresAbstract:The standard FAO methodology for the determination of crop water requirements uses the product of reference evapotranspiration (ETo) and crop coefficient values. This methodology can be also applied to soil-grown Plastic greenhouse crops, which occupy extended areas in the Mediterranean basin, but there are few data assessing methodologies for estimating ETo in Plastic Greenhouses. Free-drainage lysimeters were used between 1993 and 2004 to measure ETo inside a Plastic greenhouse with a perennial grass in Almeria, south-eastern Spain. Mean daily measured greenhouse ETo ranged from values slightly less than 1 mm day−1 during winter to values of approximately 4 mm day−1 during summer in July. When the greenhouse surface was whitened from March to September (a common practice to control temperature), measured ETo was reduced by an average of 21.4%. Different methodologies to calculate ETo were checked against the measurements in the greenhouse without and with whitening. The methods that performed best in terms of accuracy and statistics were: FAO56 Penman–Monteith with a fixed aerodynamic resistance of 150 s m−1, FAO24 Pan Evaporation with a constant Kp of 0.79, a locally-calibrated radiation method and Hargreaves. Given the data requirements of the different methods, the Hargreaves and the radiation methods are recommended for the calculation of greenhouse ETo because of their simplicity.