Optimized Fertigation Improves Yield and Quality of Cucumbers for Resource Efficiency and Economic Return in High-Tech Greenhouses

Abstract

Fertigation systems in high-tech greenhouses improve crop performance by optimising water and nutrient use, which is critical for sustainable food production. As an indicator of the electrolyte concentrations in the fertigation solution, electrical conductivity (EC) is widely used to reflect the nutrient content in the feed. This study evaluated the productivity and quality of two cucumber varieties, Lebanese, and Continental, grown under three EC levels (1.0, 2.5, and 3.5 dS/m) in high-tech greenhouses. The EC 2.5 fertigation led to the highest cucumber yields, with improvements in water use efficiency (WUE) and fruit quality. Key physiological responses, such as net photosynthesis, stomatal conductance, and transpiration rates, remained stable across EC levels, while electron transport rates were highest at EC 2.5. The study also showed significant differential expression of potassium transporter genes, which correlated with improved yield and WUE, linking nutrient management to improved plant responses. Moreover, a comprehensive cost-benefit analysis encompassing capital and operating inputs revealed that the greenhouse cucumber business in Australia can break even in 3 to 5 years. The highest net present value was recorded in EC 2.5, with Australia achieving 31.3 USD m-2·year-1 and Qatar 13.1 USD m-2·year-1. These findings suggest that optimized fertigation levels could enhance resource sustainability, plant performance, and economic viability in greenhouse cucumber production.

Keywords: electrical conductivity, post-harvest, Photosynthesis, cost-benefit analysis, mineral nutrients, sustainable food production