Farming News - Growing in a new direction
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Growing in a new direction
Peter Griffith
An increasingly urbanised world.
90% of the UK population lives in towns or cities. This is one of the highest proportions in the Northern hemisphere; outstripping our European neighbours and dwarfing China and India. This massive concentration of the population in urban areas brings with it a logistical problem for food distribution. Coupled with this British farmers and growers produce only 58% of the food we eat, down dramatically from 75% in 1994. This is particularly the case for fruit and vegetables where we import 40% of the vegetables we consume and an astonishing 90% of fruit.
image expired Growing practices need to change. One example proposed for Dubai designed by two Italian architects uses “seawater to cool and humidify greenhouses and to convert sufficient humidity back into fresh water to irrigate the crops”. To reduce the carbon footprint of each seawater vertical farm, each of the pods is covered with a transparent polymer-type membrane that allows sunlight in, negating the need to install electrical growing lights overhead, he said. “We wanted a very green model,” Girardi added. Vertical Crops become a reality. These self contained systems rely on novel hydroponics, LED lighting and climate control technology to grow produce on a vertical plan. VertiCrop is a high density, vertical growing system, which maximizes the potential of available growing space and can eliminate the need for pesticides and herbicides. VertiCrop’s sophisticated hydroponics system is capable of achieving astonishing yields; using up to 95 per cent less water than in conventionally irrigated poly-systems. Crops are continuously rotated within the VertiCrop, ensuring an even exposure to light, nutrients and creating a constant air-flow. New cropping opportunities for that farm building. image expired Further reading Food: an analysis of the issues
This importation of food and the associated distribution network generates 19 MT of CO2 per year; 3% of the UK total of green house gas emissions. Road freight is the main contributor. But congestion caused by road freight and cars traveling to and from supermarkets is the biggest cost.
The requirement to rethink how we grow and distribute food in an urban dominated society has stimulated Professor Dickson Despommier to question the whole production cycle. He thinks we have to grow food indoors in the cities and move away from traditional farming techniques. His concept of vertical farming has captured the imagination of architects around the world to design “skyscraper farms”. In conjunction with researchers in hydroponics, waste management and environmental control systems they have designed a series of potential solutions. Feasibility studies have been carried out to design buildings capable of supplying enough fresh fruit, vegetables, poultry, eggs and even grain for 50 000 people. These buildings are designed to be carbon neutral throughout the production cycle.
To keep it simple but highly powerful, Favretto said the design essentially incorporated the ancient Arab wind tower design to avoid the need for electrical fans to move air around.
Although these may seem to be futuristic the concept of incorporating internal growing areas into modern multistory buildings can be seen in the design for Vauxhall Bridge Gardens. This building has already received planning permission. The site at Vauxhall Cross lies within the Greater London Authority’s (GLA) newly designated “Nine Elms Opportunity Area”. Although not Vertical Farming this design incorporates 2,500 sq m of communal ‘sky-gardens’, each being triple height and on a full floor plate. It doesn't take much of a stretch of the imagination to see how these could become communal allotments providing fruit and vegetables to the residents.
But the idea of growing crops on a vertical plane has taken another step forward recently. Valcent Products Inc. has achieved a critical milestone with the successful launch of the company's first full scale operating unit of the VertiCropTM commercial vertical farming system at the Paignton Zoo. According to Chris Bradford, managing director of Valcent, a 100sq-metre machine, like the one installed at Paignton Zoo, can grow up to 11,200 plants per crop, which, he says, is potentially 20 times more than could be grown conventionally in a field covering the same area.
Valcent's success at Paignton zoo shows that this is now possible to grow leafy vegetables on a commercial scale. But can this technology by transferred to the farm and would it be possible to convert an existing farm building?
"We are looking to convert an existing tractor shed into a full scale vertical farming system producing salad vegetables for the UK market", says Graham Dunling of Valcent. This will meet an increasing demand as suppliers have realised the need to reduce the carbon footprint of salads imported from Southern Europe. Doubts over the sustainability of growing hectares of crops under poly tunnels in an increasingly saline environment have also concentrated the minds on the need to find a viable alternative.
It is possible to grow 12 crops per year of baby leaf salad for example and using a six metre high module the income generated can exceed £150 000 per module. Such an innovation could have multiple benefits for farming and the food industry. It would allow an alternative source of income to farmers without the need to change their land use practices and would permit land to be taken out of production to meet the requirements for the campaign for the farmed environment without fear of loss of income. It would stimulate the local economy and provide a new source of year round fresh produce without the associated food miles and with a much reduced carbon footprint.