Urban agriculture has emerged as a crucial strategy to address food security and sustainability challenges, particularly in densely populated areas. This study focused on enhancing leafy greens’ production, specifically lettuce (Lactuca sativa L.) and arugula or rocket (Eruca sativa L.), using Nutrient Film Technique (NFT) systems and automation in container-based vertical farming. The study utilized a 20-foot shipping container retrofitted to create a thermally insulated and automated growth environment equipped with energy-efficient LED lighting and precise climate control systems. The results demonstrated significant improvements in crop yields, with the NFT systems achieving productivity up to 11 times higher than traditional methods in protected horticulture. These systems enabled continuous cultivation cycles, responding to the high market demand for fresh local produce. Moreover, the integration of low-cost sensors and automation technologies, each costing under USD 300, ensured that the environmental conditions were consistently optimal, highlighting this approach’s economic feasibility and scalability. This low-cost framework aligns with industry standards for affordable technology, making it accessible for small- to medium-sized urban agriculture enterprises. This study underscores the potential of vertical farming as a sustainable solution for urban food production. It provides a model that can be replicated and scaled to meet the growing demand for healthy, locally grown vegetables.

Floating-tray hydroponics is expanding for microgreen production, yet evidence on substrate performance under natural-light greenhouses remains limited. This study compared perlite, coconut coir, and a 1:1 (v/v) perlite–coconut coir mixture for amaranth (Amaranthus cv. ‘Diablo Rojo’) grown at the end of summer in an unheated greenhouse (CRD; 4 replicates). Perlite significantly improved establishment and yield: emergence reached 72.6% versus 46.1% in coconut coir and 35.1% in the mixture, with fresh biomass of 297, 171, and 119 g m⁻², respectively. The proximate composition exhibited consistency across substrates (protein ≈ 32% DW; crude fiber ≈ 32% DW; crude fat ≈ 2.5% DW), whereas nitrate concentrations varied between 1300 and 2500 mg kg⁻¹ FW, irrespective of the substrate. Vitamin C and total phenolics showed no significant variation, and β-carotene exhibited only a slight, non-significant increase in coconut coir. In contrast, mineral composition was substrate-dependent: perlite increased Ca (3626 ppm DW) and Mg (1094 ppm DW), while P and Fe were unaffected; Na was higher in perlite. These results indicate that under natural-light, unheated greenhouses, bioactive compounds are mainly influenced by environmental variability, whereas root-zone aeration drives Ca/Mg enrichment and yield. Perlite-based floating-tray systems represent efficient, low-cost strategies with potentially lower environmental impact, suitable for scalable urban and smallholder microgreen production. These findings, derived from a single-season trial in one unheated greenhouse, should be regarded as preliminary yet consistent with previous studies on microgreens. Future multi-season and multi-species experiments will help to confirm and expand on these results.

Greenhouse tomato production in closed and semi-closed soilless systems can reduce water and fertilizer losses, but drainage reuse requires coordinated chemical, sanitary, and nutritional control. This review critically synthesizes evidence on drainage characterization, disinfection, nutrient reconditioning, and digital monitoring, with emphasis on coir-based systems. Structured searches of Scopus, Web of Science Core Collection, and PubMed were complemented by Google Scholar and reference-list screening. Evidence was classified as direct, related, transferable, or contextual according to its relevance to coir-grown tomato. Electrical conductivity and pH are necessary but insufficient because crop uptake, source-water quality, and substrate exchange processes alter individual ions. UV-based treatments can provide effective disinfection when dose, turbidity, flow, and target organism are controlled, whereas hydrogen peroxide is better supported as a complementary treatment. ToBRFV persistence in water requires virus-specific validation, and potential substrate- or biofilm-associated reservoirs remain insufficiently quantified. Only one study in the key-evidence matrix met the strict definition of direct evidence for coir-grown tomato with drainage recovery or recirculation; most sodium-management, disinfection, and monitoring evidence was therefore related or transferable. Safe reuse depends on a monitored, multi-barrier management chain with managed partial renewal when chemical or sanitary risks cannot be adequately controlled.

Soilless Culture has changed rapidly over the past decades, driven by advances in hydroponics, protected cultivation, environmental monitoring, vertical farming, and more sustainable production practices. These developments have also created new demands for undergraduate education, particularly in disciplines where scientific knowledge and technology evolve continuously. This study examined the longitudinal development of an undergraduate Soilless Culture course at Universidad de Talca, Chile, over more than twenty-five years. A retrospective longitudinal case study was conducted using institutional records, course syllabi, teaching materials, assessment instruments, practical activities, infrastructure records, and anonymized student performance data. Changes in scientific content, practical learning environments, competency development, and assessment strategies were analyzed, while final-grade records from 2021 to 2025 were summarized descriptively. Over time, the course evolved from a predominantly hydroponics-based approach to a broader curriculum incorporating substrate cultivation, recirculating nutrient solutions, and protected cultivation, toward practical work involving microgreens in floating-tray systems, nutrient solution formulation, substrate-based seedling systems, and the design or operation of recirculating NFT systems and introductory activities related to vertical farming. Practical learning environments expanded alongside disciplinary advances, and assessment progressively shifted toward authentic activities requiring students to apply technical knowledge, solve problems, justify management decisions, and communicate scientific information. Student performance remained consistently satisfactory despite the increasing complexity of the curriculum. The findings demonstrate that the long-term relevance of a specialized horticultural curriculum can be maintained through continuous evidence-informed revision rather than isolated major reforms. Unlike previous reports focused on individual educational interventions, this study documents how sustained curriculum renewal over more than two decades can preserve disciplinary coherence while progressively incorporating scientific advances, technological innovation, experiential learning, and professional competency development.