Farming the great indoors

When you think of a farm, what comes to mind? Rolling fields of green new growth, and carpets of plump, golden grains as far as the eye can see? The last thing you think of might be an unassuming warehouse or tower blocks. However, you might be surprised to learn that increasing numbers of food producers are realising it is greener to bring their plants inside.

In principle, it seems counter-intuitive. Every schoolchild knows that plants need sunlight, water, and nutrients to grow. As these are all present in the field, growing plants indoors under artificial light and heat might be expected to be inefficient at best, and environmentally destructive at worst. However, conventional farming is a carbon intensive affair. Whether it is planting the seed, applying fertiliser, harvesting, processing, or distribution, every step from field to fork requires the work of a fleet of diesel-powered machinery. Accounting for waste, each calorie we eat is the product of 12 calories of fossil fuel.

Whilst the number of carbon inputs in this simple story of traditional farming is staggering, farmers are starting to reduce the footprint of the food we eat by bringing their crops inside. In urban New York and Chicago, Gotham Greens produce lettuce, tomatoes and herbs within the city. By growing crops indoors and nearer to consumers, the length of the distribution chain can be shortened significantly, meaning that food reaches the market sooner and with a longer shelf-life. Growing indoors in a closed system also avoids the need for pesticides and herbicides, as well as negating the risks of inclement weather. The efficiency savings are particularly large for delicate plants such as salad leaves, which are especially carbon intensive and produce high amounts of waste, as anyone with a well-intentioned bag of salad in their fridge knows only too well.

As the global population continues to grow, and with climate change threatening existing farmland, the need for more space for food production can only increase. Indoor agriculture provides an important tool for relieving some of this pressure in “vertical farming”. This is the practice of growing plants indoors in soil-free conditions, in stacked layers, under LED lighting. Given the small land footprint of vertical farms, many tonnes of food can be produced from a relatively modest amount of land. Interest in vertical farming is particularly high in population-dense Singapore, Japan, and Dubai, where usable land is at a premium. The vertical approach also allows crops to be grown in spaces which would otherwise be unusable. UK-based start-up Growing Underground produce salad greens in a vertical farm housed in a network of abandoned tunnels, giving a second life to the structures originally built as air-raid shelters during WWII. Meanwhile, the unprecedented level of control afforded by vertical farming could one day enable precision farming, fine-tuning environmental inputs to provide particularly tasty or nutritious foods.

Some indoor farmers are even turning their attentions to animal proteins. Farm66 in Hong Kong, have been leading the way in “aquaponics” - integrating vertical farming with aquaculture in order to produce vegetables and fish from a single, recirculating system. We may see more complex systems in the future, incorporating longer food chains and, as researchers continue development of commercially viable crop strains capable of growing in seawater, the rearing of high-value saltwater fish could become commercially viable.

Indoor farming, of course, has its challenges. LED efficiency, fertiliser compositions, and control systems in particular loom as potential barriers to be overcome. Technologies relating to control technology for “smart” greenhouses, as well as improvements in efficient LEDs, heating, fertilisers, and the underlying hydroponic technology could be immensely valuable. However, the seeds have been sown, and inventors who overcome these hurdles and obtain robust patent protection for their inventions will surely reap the fruits of their efforts.

This blog was originally written by Andrew Tindall.