What is hydroponics - and is it the future of farming?

While industrialized farming techniques have meant a more plentiful supply of cheaper, fresher food – most notably in the developed world – they can also be a threat to the environment, promoting waste, putting too much strain on resources and causing pollution. That’s one of the findings of a report published by the Ellen MacArthur Foundation at the World Economic Forum Annual Meeting in Davos.

The report highlights the importance of cities in the production and consumption of food: “80% of all food is expected to be consumed in cities by 2050, they have to be central to this story. Today they often act as black holes, sucking in resources but wasting many of them – the final stop in the take-make-waste approach.”

Partly, this is due to the need to transport food to urban areas. That’s a process that places great importance on producing a lot of food, then packing and shipping it across sometimes vast distances, before storing and finally selling it to people. From start to finish that requires resources to be deployed at every step of a long chain of events – fuel, people, land, buildings, the list goes on.

One response to this, which is beginning to take shape, is vertical farming. Forecasts from Research & Markets claim the vertical farming industry could be worth as much as $3 billion by 2024. Key to this approach, where food is grown in densely populated towns and cities where land is scarce, is the use of hydroponics.

The plants you don’t actually plant

Essentially, hydroponics is the process of growing plants without using soil, which might sound counterintuitive to anyone unfamiliar with the practice. The word itself is an amalgamation of two Greek words: hydro, meaning water and ponein, meaning to toil. Plants are rooted into a variety of compounds, including vermiculite, rockwool, or clay pellets – inert substances that won’t introduce any elements into the plant’s environment. Nutrient-enriched water then feeds the plant.

Hydroponics offers one particular advantage over traditional growing methods. Through careful manipulation and management of the growing environment, including the amount of water, the pH levels and the combination of specific nutrients plants can be encouraged to grow faster. Air and soil temperatures can also be carefully controlled, as can the prevalence of pests and diseases.

The net effect is an increased yield and improved use of resources. A less wasteful approach to resource consumption means reduced waste, preservation of water stocks and a diminished reliance on pesticides, fertilizers and other potentially harmful materials.

A holistic view of supply and demand

Around one-third of all the food produced each year ends up being wasted, according to the UN Food and Agriculture Organization. That’s approximately 1.3 billion tonnes, which equates to a loss of almost $1 trillion.

The point in the value chain at which food tends to get wasted most differs between developed and developing countries. In developing countries, losses and waste tend to occur during the earlier stages of the food value chain. Reasons for that include constraints around farming, crop management and harvesting caused by a lack of finances and expertise. Improving the infrastructure and logistics of food in developing nations can help address many of these challenges.

Perhaps less surprisingly, in higher-income countries food is generally wasted later in the process. Often that is driven by consumer behaviour and retailers’ approach to in-store discounting practices; discounts that fail to attract purchases while food approaches the end of its “eat-by” period invariably lead to waste and loss. The situation is further hampered by ineffective strategies for taking unsold food and finding other destinations for it – such as, but not limited to, homeless shelters.

Consumers in rich countries waste almost as much (222 million tonnes) as the entire net food production of sub-Saharan Africa (230 million tonnes). Meanwhile, the UNFAO says the number of malnourished people is on the rise: in 2016, it stood at 804 million but the following year had grown to 821 million.