Evaluation of the Microclimate in a Traditional Colombian Greenhouse Used for Cut Flower Production

Edwin Villagrán,Jorge Flores-Velazquez,Carlos Bojacá,Mohammad Akrami

doi:10.3390/agronomy11071330

Edwin Villagrán, Jorge Flores-Velazquez + Show 2 more

Open Access

https://doi.org/10.3390/agronomy11071330

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Abstract

Cut flower production in the Bogotá savanna is one of Colombia’s main export products. Flower production is mainly carried out in greenhouses, as this type of production system has substantial advantages over crops grown in open fields. Protected agriculture provides timely climate management that improves crop yields. The objective of this work was to build and validate a 3D CFD numerical model to understand the spatial distribution of temperatures because of the air flow dynamics inside a typical greenhouse in the Bogotá savanna. Root mean square error (RMSE) and mean absolute percentage error (MAPE) were the statistical indicators used between experimental and simulated wind speed and temperature data. The simulations considered twelve evaluation scenarios that were established based on the climatic conditions characteristic of the study region. The results indicate that under regional conditions of temperature and wind for this type of passive greenhouse, there is a deficient ventilation rate. This rate does not exceed 35 exchanges h−1 compared to the recommended rates for crops, which is between 45 and 60 air exchanges h−1. This renewal rate contributes to the heterogeneity of the microclimatic dynamics of the greenhouse, presenting hot spots with temperature values above 32 °C in all examined scenarios. For the lower air speed scenarios (<1 ms−1), these areas of high temperature can reach up to 50% of the cultivated area. Therefore, it is suggested that future studies should seek technical solutions to optimize the microclimatic conditions of the greenhouse design used in the Colombian floriculture sector.

Highlights

One of the most relevant characteristics that influence the performance of crops grown in covered agricultural production systems is the generated microclimate inside the different kinds of greenhouse designs used around the world [1,2]
It was found that the predictions made by the computational fluid dynamics (CFD) model for temperature were within the trend reported experimentally, and the wind speed values coincide with the values predicted by the numerical model
An experimentally validated 3D CFD model was used to simulate the behavior of air flows inside a traditional Colombian greenhouse under the conditions of four wind directions (S1, S2, S3, and S4) and four wind speeds (V1, V2, V3, and V4) in the outdoor environment

Summary

Introduction

One of the most relevant characteristics that influence the performance of crops grown in covered agricultural production systems is the generated microclimate inside the different kinds of greenhouse designs used around the world [1,2]. Microclimate conditions generated inside the structure will be dependent on the air flow patterns, the climatic conditions of the external environment, and the heat and mass exchanges between the plants and the soil and between the plants and the air [3]. These microclimate conditions will positively or negatively affect physiological processes, such as photosynthesis and evapotranspiration, that directly influence the growth and development of the crop [4,5]. In the traditional Colombian greenhouse, microclimatic management is carried out through the opening and closing of ventilation areas located on the four sides of the greenhouse, trying to take advantage of the air flows generated by wind or thermal buoyancy that are part the phenomenon of natural ventilation [8,9]

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