The Food and Agriculture Organization states that the demand for cereals, both for human consumption and animal feed is projected to be three billion tonnes by 2050. In developing countries, the increase in food production will need to more than double (2009 FAO article entitled "Global agriculture towards 2050"). Another set of heat-maps and graphs from the World Resources Institute projects water-stress levels all the way up to 2040 on account of factors such as global warming, urbanisation, shift in agriculture patterns towards animal-based food production and increasing populations in developing countries.

At the same time, the jury is out on what initially appeared to be promising solutions. Aquaponics, hydroponics, greenhouses, vertical farming, artificial light and similar. Take vertical farms as an example. Andrew Jenkins, research fellow at the School of Natural and Built Environment at Queen's University Belfast, indicates that a square metre patch of lettuce grown in a traditional greenhouse requires 250kWh of energy a year. In comparison, lettuce grown in a purpose built vertical farm needs an estimated 3,500kWh a year for the same square metre. Similar studies on the economics of vertical farms indicate that energy costs take up 40 per cent of the total cost of production. Which in turns leads to carbon emissions.

One possible solution that is more closely linked to traditional sustainable architecture has been brought to the Middle East by Atle Idland, founder, general manager and managing director of Desert Control Middle East. The proposition is that it does not require heavy upfront investment from farmers and is not energy intensive.

The solution was originally patented by Norwegian scientist Kristian Morten Olesen. Since 2005 he has been working on Liquid Nanoclay (LNC), a process to mix nano-particles of clay with water and bind them to sand particles in order to condition desert soil.
He says: "With this process we can change any poor-quality sandy soil into high-yield agricultural land in just seven hours."
According to him, the process involves creating a half-metre deep layer in the soil that turns it fertile. Olesen continues in the company he founded, Desert Control in Norway as the chief technology officer. The chairman and CEO is now Brage Johansen, who says: "I have worked with cleantech and greentech for a decade and I have never seen a solution with more global potential than this. Greening of desert areas will contribute to ten of the UN's seventeen Sustainability Goals."

Liquid clay. Norwegian scientist Kristian Morten Olesen has patented a process to mix nano-particles of clay with water and bind them to sand particles to condition desert soil - he has been working on Liquid Nanoclay (LNC) since 2005."The treatment gives sand particles a clay coating which completely changes their physical properties and allows them to bind with water," he says.

"This process doesn't involve any chemical agents. We can change any poor-quality sandy soils into high-yield agricultural land in just seven hours."

Kristian's son Ole Morten Olesen, who is also the chief operating officer of the company they founded, Desert Control, says: "We just mix natural clay in water that is inserted into the sand which creates half a metre layer into the soil that turns the sand into good fertile soil."

Normal sand particles are very loose, which means that they have a very low water retention capacity. But when you add Liquid Nanoclay to the sand it binds those sand particles together, says Kristian, which means it can hold water for longer, "increasing the possibility of agricultural yield". The cost of treatment per hectare (2.4 acres) of desert varies from $1,800-$9,500 (£1,300-£6,900) depending upon the size of the project - which currently makes it too expensive for most farmers. The soil requires a 15%-20% retreatment after four or five years if the land is tilled and if untilled then the treatment lasts for longer.
Read also the BBC article The innovation turning desert sand into farmland (second link)