Akademik Veri Yönetim Sistemi
Tarim Bilimleri Dergisi, cilt.15, sa.1, ss.65-73, 2009 (SCI-Expanded)
In this study, a mathematical model was developed to define heat and mass transfer processes by microclimatologic methods in the greenhouse crops. The crop structure was depicted by means of plant architectural parameters and distribution functions. The energy and mass balances were identified for a differential stratum of the plant stand. The model contained the processes such as the solar radiation fractions (total, PAR and NIR), net radiation; water vapor and CO2 transfer for different levels of plant stand. The sensible heat flux from leaf surfaces was computed by using resistance concept according to an analogy between electrical current and heat flux, and this analogy was adapted to both water vapor and CO2 transfer. The model was simulated for a period of 24 hours using the crop stand inputs and variables. According to the simulation results, the penetration rates of total solar radiation for z=1 m and z=0 m was %49 and %32.3 respectively. The net radiation was computed as 10 and 289.4 W/m2 for simulation day. The daily integrations crop transpiration and soil evaporation were determined as 2.731 kg/m2 and 1.478 kg/m2 respectively. As a result of these integrations, the evapotranspirasyon was 4.209 kg/m2.day The validation of model was performed with regression analysis to determine correlations between simulation results and measurement data. As a consequence, the model developed can be employed as a tool determining the heat and mass transfer processes for greenhouse crops, and can be integrated with expert systems to provide a more effective climate management.