Comparison of Selected Costs in Greenhouse Cucumber Production with LED and HPS Supplemental Assimilation Lighting

Abstract

The amount of energy used in agricultural production, processing and distribution is constantly increasing. During the winter months in the greenhouse production industry, the supplemental lighting required to keep up production levels results in high expenditure. Current technology uses broadband high-pressure sodium (HPS) lamps, which is not the most efficient light source for crop production. Recent breakthroughs in the development of light source technologies have led to new opportunities for the use of sustainable and highly efficient light sources in the form of LEDs (light-emitting diodes) for greenhouse lighting. The aim of the study was to evaluate the efficiency of using photosynthetically active radiation (PAR) light for cucumber yielding, production processes and its influence on the variable costs in the cultivation of cucumbers using three different types of lighting. The research was carried out using three individual greenhouse growing area compartments, whereby the plants contained within were lit using three combinations: 1. HPS standard illumination from top HPS sodium lamps—control, 2. HPS-LED—HPS toplighting and LED interlighting, and 3. LED-LED—100% LED lighting, both toplighting and interlighting with LED. The research was conducted in two independent winter crop cycles. The results of the research conducted indicate that the efficiency of light use was the highest in the LED-LED combination and the lowest in HPS, and the use of supplemental lamp lighting in the LED-LED combination (interlighting and toplighting) gives the most favorable surplus of all the variable costs over the value of production to be obtained. Despite the highest absolute level of variable costs in this type of supplemental lighting, the production value was higher by as much as 32.55% in relation to the HPS combination, which also translated into a gross margin that was higher by about ¾. However, it is worth pointing out that, in the HPS-LED combination, the share of lighting and heating costs in the total value of production was the lowest. It is also a combination currently recommended in the literature as being the most beneficial in greenhouse production.

Smart greenhouses as the path towards precision agriculture in the food-energy and water nexus: case study of Qatar

“…In the literature, numerous comparative studies have been carried out to assess the effectiveness of each technology. For instance, three are different types of lighting, namely HPS standard lighting, HPS top lighting and LED inter-lighting, and 100% LED lighting have been tested in a lettuce greenhouse, and the results indicated that the efficiency of light use was the highest in the 100% LED combination and the lowest in HPS (Kowalczyk et al 2020). Also, a comparison of 1000 W HPS lighting system versus 650 W LED lighting system has shown that LED lighting has 38%-47% less environmental impact in terms of global warming, ozone depletion, and acidification than HPS lighting system (Zhang et al 2017).…”

Effects of LED supplemental lighting on the growth and metabolomic profile of Taxus baccata cultivated in a smart greenhouse

“…Given these premises, and due to their physical characteristics (narrow spectral bands, nonthermal photon emission, longer life, energy saving), LED lamps with a combined red and blue spectrum are currently the most widely used light source to optimize growth and metabolism of plants in a controlled environment [7][8][9]. The physical properties of LEDs make them suitable for use both in intra-canopy (aka, inter-lighting) and top-lighting systems [10], and both in horticulture and ornamental plants production, allowing reductions in energy consumption while maintaining optimal photon flux values of the incident radiation; for this reason, they are a valid source of light energy in greenhouse environments, especially during the winter season, exerting positive effects on crop quality, disease resistance, and bioactive compounds content [9]. Supplemental LED inter-lighting, relevant in particular for high-wire vegetable cultivations, has proven to increase yield and improve fruit quality in various all-year round greenhouse crops [11].…”

A New Index Assessing the Viability of PAR Application Projects Used to Validate PAR Models

“…For instance, PAR is among the main variables to bear in mind when assessing the growth of biomass [1][2][3] or microalgae [4][5][6][7]. Many greenhouses use artificial lamps to replicate solar light, and there is an interesting field of research exploring the best lamp spectrum for different crops [8,9]. PAR is also of interest for gross primary production (GPP) [10], terrestrial net primary production (NPP) [11], and PAR use efficiency [12].…”