Sustainability Perspectives of Organic Farming and Plant Factory Systems-From Divergences towards Synergies

Closed plant production systems are generally considered sustainable. Such systems are capable of minimizing externalities due to resource recycling. There are two systems, apparently diverging, recently considered as the counterparts of today's conventional agricultural practice: organic farming (OF) and plant factories (PFs). With a strong regulatory background, OF integrates plant production into natural ecosystems by minimizing agrochemical use, while PFs create an artificial environment where all factors can be fine-tuned according to the needs of the crop. In this study, both systems are investigated based on their similarities and constraints; for this, three pillars of production were selected as indicators and reviewed for sustainability based on literature data: I. regulatory background, II. growing media use, III. species use, along with certain socio-economic factors. The reasons for co-existence were highlighted in every aspect. Alternatives for sustainable growing media use are introduced. PF-targeted species selection and variety breeding are necessary to maximize facility utilization. The main barriers to system interoperability are identified in growing media use and regulatory restrictions. The present global processes envisage the trends of the future, such as threats of living ecosystems, plant species allocation, urbanization impacts, agricultural intensification, economics of PFs, local supply chains, education about OF and PFs, consumer acceptance of OF and PF products, and discrepancies in global regulations. These aspects will certainly trigger further research in the scientific community.