Journal of Experimental Agriculture International

Hydroponics and aquaponics are increasingly presented as sustainable alternatives to soil-based vegetable production, yet their environmental and socio-economic performance varies markedly with system design, crop choice, climate, energy supply, management competence and assessment boundary. This critical narrative review evaluates the evidence on the capacity of these systems to support sustainable vegetable production, with emphasis on agronomic performance, water and nutrient use, life-cycle impacts, biological and food-safety risks, economic feasibility and conditions for responsible scaling. Literature published from 1999 to 20 May 2026 was identified through accessible scholarly indexes, metadata services, publisher records and citation searching, and was selected according to relevance, methodological transparency and evidential contribution. The strongest evidence indicates that recirculating hydroponics can achieve high land and water productivity and precise crop control, particularly for leafy vegetables and herbs. These advantages are conditional because electricity, climate control, fertiliser manufacture, infrastructure and growing media can dominate environmental burdens. Aquaponics can integrate fish and vegetable production and recover a portion of aquaculture nutrients, but it does not automatically create a closed nutrient cycle. Feed-derived inputs, incomplete mineralisation, nutrient imbalance, pH conflicts, solid residues and system complexity constrain circularity and crop performance. Decoupled configurations can improve biological optimisation and nutrient management, although they add components and may weaken claims of operational simplicity. Across both technologies, comparisons are frequently limited by short experiments, inconsistent functional units, selective reporting of water or yield benefits, and sparse commercial-scale data. The review concludes that sustainability should be treated as a context-dependent system property rather than an intrinsic attribute of either technology. Credible deployment requires low-carbon energy, effective recirculation and sanitation, transparent mass balances, crop-system matching, skilled management, viable markets and governance that evaluates multiple outputs and risks. Future research should prioritise harmonised reporting, long-duration commercial trials, multi-output life-cycle and economic assessment, microbial risk management and region-specific transition pathways.