Vertical farming increases lettuce yield per unit area compared to conventional horizontal hydroponics

Area of Science:

• Agricultural Engineering
• Horticultural Science
• Controlled Environment Agriculture

Background:

• Vertical farming systems (VFS) aim to increase crop productivity by utilizing vertical space.
• Comparing VFS with traditional horizontal hydroponic systems (HHS) is crucial for evaluating their viability.

Purpose of the Study:

• To compare the productivity and light distribution of a VFS against a HHS.
• To assess the potential of VFS as an alternative to conventional farming methods.

Main Methods:

• Lettuce (Lactuca sativa L. cv. "Little Gem") was grown in both VFS and HHS under controlled indoor conditions.
• Plants were grown in perlite with half-strength Hoagland's solution and artificial lighting.
• Photosynthetic Photon Flux Density (PPFD) and shoot fresh weight were measured.

Main Results:

• PPFD and shoot fresh weight decreased significantly from the top to the base in the VFS.
• Despite this gradient, the VFS produced a higher crop yield per unit of growing floor area compared to the HHS.

Conclusions:

• Vertical farming systems (VFS) are a viable and attractive alternative to horizontal hydroponic systems (HHS).
• Optimizing artificial lighting within VFS could lead to further significant increases in crop yield.