Optimizing Cucumber Productivity: Impact of Fertigation Systems, Growing Media, and Nutrient Solutions in a Protected Soilless Environment

A study employing a factorial split‐plot design with three replications over three growing seasons was undertaken to evaluate the effectiveness of an automated fertigation system for cucumber (cv. Multistar) under protected cultivation, in comparison with a conventional fertigation system. The experiment included three fertigation treatments: (i) 100% fresh nutrient solution, (ii) fresh solution mixed with leachate at a 9:1 ratio (v/v), and (iii) fresh solution mixed with leachate at an 8:2 ratio (v/v), tested across three growing media: (i) cocopeat + cocochips (1:1), (ii) cocopeat + cocochips (7:3), and (iii) cocopeat alone. The leachate used in the study consisted of moderately concentrated, nutrient‐rich drainage water collected from previous irrigation events. Results revealed that the automated fertigation system significantly improved plant growth, yield, and fruit quality over the conventional system, increasing vine length from 3.93 to 4.36 m, leaf area index by 8.9% (3.17 vs. 2.91), average fruit weight by 6.4%, fruit length by 5.1%, and fruits per plant by 10.7%. Pooled analysis showed an 18.9% increase in total yield under automated fertigation. Among substrates, cocopeat + cocochips (7:3) performed best, recording the highest yield (3.25 kg plant −1 ), followed by cocopeat alone (3.02 kg plant −1 ) and cocopeat + cocochips (1:1) (2.69 kg plant −1 ). Fruit quality also improved under automated fertigation, with increases in firmness (14.4%), antioxidant capacity (10.6%), total chlorophyll (6.2%), phenol content (4.1%), and total soluble solid (5.4%). Yield and quality did not differ significantly among fertigation treatments, indicating that leachate reuse up to 20% does not compromise productivity. Overall, the study highlights the potential of automated, resource‐efficient fertigation strategies for sustainable and high‐quality cucumber production in soilless protected cultivation systems.