The Role of Plant Growth-Promoting Microorganisms (PGPMs) and Their Feasibility in Hydroponics and Vertical Farming

There are many reasons for the increase in hydroponics/soil-free systems in agriculture, and these systems have now advanced to the form of vertical farming. The sustainable use of space, the reduction in water use compared to soil-based agriculture, the lack of pesticides, the ability to control nutrient inputs, and the implementation of user-friendly technology for environmental control and harvesting are all factors that have made the global market for vertical farming predicted to reach more than USD 10.02 billion by 2027. By comparison, soil-based agriculture consumes 20 times more water, and some agricultural practices promote soil deterioration and cause environmental pollution. Plant growth-promoting microorganisms (PGPMs) have been used extensively in traditional agriculture to enhance plant growth, environmental stress tolerance, and the efficacy of phytoremediation in soil-based farming. Due to the controlled atmosphere in hydroponics and vertical farms, there is strong potential to maximize the use of PGPMs. Here, we review the leveraging of plant growth-promoting microorganism mechanisms in hydroponics and vertical farming. We recommend a synchronized PGPM treatment using a biostimulant extract added to the hydroponic medium while also pre-treating seeds or seedlings with a microbial suspension for aquaponic and aeroponic systems.

Automated summary

There are various reasons for the increasing popularity of hydroponics/soil-free systems, which have evolved into vertical farming. The benefits of utilizing space efficiently, reducing water consumption, avoiding pesticides, controlling nutrient inputs, and incorporating user-friendly technology have contributed to the predicted growth of the global market for vertical farming to exceed USD 10.02 billion by 2027. In contrast, conventional soil-based agriculture uses significantly more water, promotes soil degradation, and causes environmental pollution. Leveraging plant growth-promoting microorganisms (PGPMs) in hydroponics and vertical farming could optimize their potential, with recommendations for synchronized PGPM treatments using biostimulant extracts in the hydroponic medium and pre-treating seeds or seedlings with microbial suspensions for aquaponic and aeroponic systems.