Optimizing nutrient solution (NS) management in hydroponic systems is crucial to promoting sustainable food production whilst maintaining crop productivity and quality. Sweet basil was used to investigate how nutrient reduction and wastewater-fed MFC catholyte (WW) used as a source of Nutrient, with/without gypsum supplementation, affected growth and yield. Three experiments were conducted: (1) stepwise NS reduction (100, 75, 50, 25%); (2) stepwise NS reduction (80, 60, 40, 20%); and (3) NS substitution (100% NS; 50% NS + 50% WW; and 50% NS + 50% WW + 0.46 mM gypsum. In general, across the NS dilution experiments, basil response to treatments was nonlinear and trait specific—leaf canopy and biomass accumulation traits were sensitive to treatment, with a breakpoint in response at low NS, while moderate NS reductions produced growth similar to controls. In experiment 1, shoot biomass accumulation and leaf area were indistinguishable from control when NS was diluted from 100% to 50% but declined at 25% NS, indicating a potential breakpoint. In experiment 2, most measured growth traits peaked at 60% NS. In experiment 3, the WW-NS substitution resulted in a biomass penalty, with total phenolics lowest under 100% NS, intermediate under 50% NS + 50% WW, and highest during supplementation with gypsum. Overall, the outcome of our study suggests a promising window for making hydroponically grown basil more sustainable, based on a reduced total NS supply plus a substitution of 50% of this reduced NS with WW, and possible methods for controlling biomass quality.
- Open Access
- Article
The Sustainability of Basil Production in Hydroponics Can Be Increased Using Low-Nutrient Regimes Incorporating Biofertiliser from Microbial Fuel Cells
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Received: 21 Apr 2026 | Revised: 25 Aug 2026 | Accepted: 30 Sep 2026 | Published: 13 Oct 2026
Abstract
Keywords
hydroponics | nutrient management | microbial fuel cell catholyte | wastewater nutrient recovery
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