An article in The Guardian today says that Ocado have bought into a ‘vertical farming.’ They are already claiming that it is pesticide free and sustainable.
This is nothing new, the idea has been around for years and was once known as hydroponics where plants are grown in soil less systems. The roots can be contained in blocks of inert media like rock wool or just dangle into water filled troughs.
The ‘vertical farm’ uses trays of plants with lighting above them. The lights used to be energy hungry, but the advent of LEDs has reduced the energy requirement. That is probably where the sustainability claim originates.
What the investors will not tell you is that plants need nutrients to grow, In conventional growing nutrients come from soil. In hydroponics they have to be dissolved in water.
The basic plant food is NPK, nitrogen, phosphorous and potassium. These can only be supplied by using artificial fertilizer manufactured in chemical plants. Phosphorus is mined and there are many reports of the devastation this has caused. There is also grave concern about how shortages of phosphorus “could leave us all hungry”
Artificial fertilizers require huge amounts of energy and raw material from around the world which cannot, by any stretch of the imagination be considered as sustainable.
Soil contains many micronutrients that are impossible to synthesize in an artificial form. Some hydroponic enthusiasts will tell you they include micronutrients in their mixes, but it is not as simple as adding a few more chemicals.
The only place to grow food is in well managed soil. Making artificial food factories might look attractive, especially to investors, but it is not the way forward and looks like another quick techno fix to a complex issue. So, why do it? As Ocado say, they are looking for big returns.