A lot of urban farming success stories have now been because of the installation of vertical farms. This technology is based on hydroponics or aquaponics and are built within city limits. I am not in favour of these farms and wanted to present my arguments to y’all. I have not looked at the numbers of carbon footprint figures of hydroponics and aquaponics, so my argument is one based on principles.
Humidity and temperature are maintained in these massive spaces to ensure the plants get a healthy and constant environment to grow in. These need massive HVAC systems. So these vertical farms are very energy intensive and costly. A small farmer will not be able to raise funds to do such a heavy CAPEX set up. I feel: if there is anything a small farmer can’t pursue on his own, we shouldn’t be pursuing that on scale.
The nutrients for the crops to grow are manufactured in a centralised factory overseas. The carbon footprint of importing such large volumes of fertilizers is another mark down for hydroponics.
When we look at agriculture as it was practiced in a majority of succesful settled human civilizations, it has mostly been cultivation of crops in the same soil repeatedly over several years. The nutrients in the soil are regenerated by varying techniques such as application of manure, cover cropping, mulching and crop rotation amongst others. This ensured continuous supply of nutrition to the soil and food to the people. People therefore respected soil like God and gave it the attention it deserves. The biggest carbon sink in the planet, arguably, is soil (or is it the oceans?). The absence of soil in hydroponics makes it impossible for hydroponics to be carbon positive. In my opinion, this is the most significant con in the pros & cons list for hydroponics.
While Hydroponics rates high on the reduced carbon footprint of transporting vegetables to the end consumer, its net carbon footprint of producing the food is immensely high for it to be a part of the sustainable movement for long. It is the same reason why I think it shouldn’t be accorded the same due as organic or natural farming.