Within the Fieldlab Vertical Farming, a comparative study on the cultivation of basil was conducted in the indoor cells of participants Delphy Improvement Centre, Philips Horticulture LED Solutions (Signify), Vertify and Logiqs. The cells are different in size and technical set-up. This study was done to test the following research question:
• If we use the same input settings in all four cells, do we realize the same macroclimate conditions (in the space above the plants)?
• Do we realize the same microclimate conditions (between the plants)?
• Do we realize the same plants in terms of morphology, weight and quality at the end of the trial?
This study is a follow up of an earlier comparative study between the cells of WUR Bleiswijk and Delphy within Fieldlab Vertical farming.
In this experiment we cultivated basil with the exact same growing recipe for the four participating locations in terms of light, climate and fertigation. Although the climate setpoints were the same, some differences in macroclimate between the cells were observed. The difference (ΔT) between temperature on cell level (macroclimate) and temperature on plant level (microclimate) was different among the cells, and differed between different moments in time. Notable was that the leaf temperature was lower than the air temperature, and that this difference was in most cases bigger in the dark period rather than in the periods with the LED lights on.
The plants grown in the different cells were quite different at the end of the trial, after 28 days. The plants grown in the cell of Signify were remarkably more elongated than from the other cells. The plants of Delphy had a similar fresh weight to those of Signify, but the biomass distribution was different with a higher percentage of biomass allocated to the leaves in Delphy's plants.
The differences found between the cells were the result of the influences of the growing environment on the plants. This resulted in a microclimate in the canopy that was different from the climate computer controlled macroclimate in the cells. The extent to which the macro- and microclimate differs, seems to be determined by the technical design of the facility.