Open field, vertical and greenhouse farming
Row-crop farming has been the bad guy for a while.
Between applying fertilizer and driving big machinery, farming seems to hit all the wrong notes with the eco-friendly crowd.
But what is the alternative?
Heading toward a greater portion of plantbased foods in our diets means more intensive row-crop farming to keep up with the production. We also have to consume more plantbased foods to get our daily caloric needs filled in a pound-forpound comparison with meat.
Let’s say that plant production ramps up, not with an increase in row-crop farming but with the vertical farming movement.
Vertical farms have promised to deliver fresher produce on less energy and/or carbon usage than farming in a field, outside.
Is that true?
The University of Oxford digs in with a study called “Regional conditions shape the food–energy–land nexus of lowcarbon indoor farming,” authored by Michael W. Hamm from Michigan State University, Florian Forster from Energy Infrastructure Partners (Switzerland), Aidong Yang from the University of Oxford, and Till Weidner, also from the U of Oxford.
This study was published in the journal Nature
Food on February 28th. In it, the researchers compared the yields of six vegetables in different farming methods, including open-field farming (the ‘normal’ way to farm), vertical farming, and greenhouse farming- which is farming in the ground but with a greenhouse over it. Those six veggies were bell peppers, broccoli, lettuce, tomatoes, spinach, and summer squash.
If we just compare land usage on their faces, the open-field farming method would lose every time. It uses more land to produce less food than vertical farming or greenhouse farming.
However, this landmark study dug a little deeper.
It took the land on which the vertical farms and greenhouses are located -- and added to it the land needed to produce the energy those methods require for production. It takes energy to heat those buildings and also to light them, both of which are factors that improve the yields of the crops grown in those methods.
The study measured the land needed to produce renewable energy -- a key component to being carbon-neutral, which is something that vertical farming capitalizes on.
Vertical farms, greenhouses, and open-field farming were compared in nine cities: Reykjavik, Stockholm, Boston, Tokyo, Santiago, Johannesburg, Phoenix, Singapore,
and the United Arab Emirates.
The study’s results were somewhat surprising!
It turns out, the land requirements (including for energy production to maintain the indoor methods of farming) depend on the climate.
It’s all about location, location, location. Colder places could possibly utilize greenhouse and vertical farming methods to reduce the production land footprint, but warmer locations should stick with openfield farming if the goal is to reduce the land requirements.
And that isn’t to say
that greenhouse farming or vertical farming will produce more food at a lower cost than open-field farming. While their land footprints are smaller than open-field farming, the cost per unit produced is still much higher in vertical and greenhouse farming.
So is it better to eat open-field-farmed produce? From a vertical farm? Which is ‘greener’ -- from a greenhouse or from a field?
The answer, as always, is much trickier than a simple ‘yes’ or ‘no.’
It all depends on where you place the most value.