Air from ventilation systems gives vegetables a boost

About the episode

How do we keep cities green, make better use of space on our rooftops, and ensure we have enough food? By using the air from ventilation systems more intelligently, think American researchers.

Rooftop gardens already exist, of course, but the plants growing there have to deal with more solar radiation, more wind and less humidity due to the substrate in which they grow. This results in less healthy and smaller plants. That’s why they looked on the roof of Boston University to see if they could do anything about it.

The test was carried out with spinach and corn. These have been designed in such a way that the air from the ventilation system – which contains a higher concentration of CO2 – can reach the plants well. Spinach was expected to do well here, maize was instead used as a control plant to check whether the use of ventilation air could also have other consequences for the plants.

During the experiment, things like plant size, number of leaves and total biomass were measured and what they saw: Fanned spinach had four times the biomass of spinach from unventilated roof.

Now, a number of things still need to be studied, for example, what flow rate is ideal for the air. Also, biomass does not say everything and: don’t we just want to capture CO2? Instead of pumping it through the air through the vegetable patch? But until then, it might not hurt to try this – if possible.

Read more: A Breakthrough in CO2 Ventilation Could Turn City Rooftops into Wonderful Vegetable Gardens