Modeling the suitability of the traditional plastic greenhouse for tomato production across Colombian regions
Registro en:
instname:Universidad de Bogotá Jorge Tadeo Lozano
reponame:Repositorio Institucional de la Universidad de Bogotá Jorge Tadeo Lozano
Autor
Diaz, D.C.
Bojacá, C.R.
Schrevens, E.
Institución
Resumen
Greenhouse tomato production in Colombia has increased at a rate of 250 t
year-1 in the last decade, but yield has remained constant around 106 t ha-1 year-1. The
main reasons for this trend is that greenhouses used for tomato cropping are still
vulnerable to the high seasonal and intraseasonal climate variability in the Equatorial
Zone. To obtain information about the relation between outdoor and indoor
environments, we analyzed productive areas with a greenhouse climate model (GCM).
The GCM was calibrated, validated and used to simulate the thermal behavior of
traditional greenhouses under different climate conditions in Colombia. The input
climate variables included global radiation, outside air and soil temperatures, relative
humidity and wind velocity recorded at six locations. The locations are situated
between 2000 and 3000 m a.s.l. with average temperatures between 10-20°C
characterized by unimodal or bimodal rainfall regimes. Automatic weather stations
recorded the hourly climate data during tropical wet and dry seasons. The modeled
greenhouse was a naturally ventilated plastic one with a floor area of 5670 m2, surface
of the cover including side walls of 9610 m2, and maximum roof and side ventilation
area of 324 and 370 m2, respectively. The simulations were carried out with the
presence of a tomato crop. The simulations showed that traditional structures keep
appropriate temperatures for tomato, mainly during the dry season at the six
locations. The wind profile for each season explained these results, affecting the
efficiency of natural ventilation. The change in the wind profile is due to the
meridional migration of the intertropical convergence zone throughout the year.
Therefore this atmospheric system is a factor to take into account when designing
sidewall and roof ventilation openings. For cold marginal tomato production areas,
predictions showed the potential to explore passive heating systems to improve the
climate during night hours.