Man has always faced challenges in the desert. Due to climate change, arid lands have been increasing. Whether it is with the aid of new technologies or millennial wisdom, here is how we can grow food from the dry sands.
Each oasis has a distinct type of irrigation system: for example, in the Sahara, Ghardaya in the valley of Mozab, water flows under a dry bed of an ancient river. Over one million date palms are irrigated by way of a capillary system of dikes, dams and wells that channel, sort and dispense water, ensuring that just the right amount will reach the gardens.
The oases of Souf, Algeria
In the region of the Souf, south-east of Chott Melrhir, the water table is close to the surface. The system of oases is an example of an ingenious method to water the palm groves, through the technique known as Ghout. Instead of irrigating the surface by use of wells and canals, basins are dug for the palms, so that their roots reach the water in the aquifer directly. It is a plan that avoids water losses due to evaporation and offers plantations effective protection against wind and sand.
Project Oasis Josefowitz in Israel
Near the agricultural research station Hatzeva Yair, a team of scientists at Ben-Gurion University has developed and tested a structure for the sustainable production of fruit and vegetable crops in arid areas. In the southern regions of Israel, rains are scarce and the average temperature in August is 50 ° C. An experiment in progress since 2010 and inspired by permaculture, it has already proven that fruit trees can be grown in the desert. A series of agricultural experiments have tested different qualities of irrigation water and four different crops.
Sand nanotechnology, United Arab Emirates and Germany
La Dime, a company of the United Arab Emirates, and the Fraunhofer Institute in Freiburg have developed a revolutionary nanotechnology to create a waterproof hydrophobic sand that can be spread in a thin layer directly beneath the desert sand. The goal is to prevent the evaporation of precious moisture that forms in the desert at night, making it available to the plant roots. They have already conducted an experiment just two kilometers from the Dead Sea, where rain rarely falls and the temperature in August is 50 ° C and where this nanotechnology sand is already in the production phase.
The Sahara Forest Project in Qatar
It is possible to create cultivation systems near the coast by combining the technology of greenhouses and seawater with that of solar thermodynamics. The proximity of the sea guarantees the constant presence of water that is sent to a desalination plant, using a solar energy pump. In short, you use what you have in abundance to produce what is needed most. With a vast desert area, sunlight, salt water and CO2 can produce food, water and clean energy. The first project was commissioned by the government and funded by Yara International ASA and the Qatar Fertiliser Company. It covers an area of 10 thousand square meters in the vicinity of Measaieed, an industrial city of Qatar. The plant has already produced its first crop of cucumbers.
The green dots in Saudi Arabia
In a series of satellite images, NASA has documented the evolution of farming in the Saudi desert from 1987 to the present, showing the emergence of huge green dots. Each dot is a field about a mile in diameter and is sprayed with water by means of systems rotating from a water reserve that cannot be reconstructed, as it was formed before the last ice age, about 20,000 years ago. Rain (in the Saudi desert about 100-200 mm of water per year) is not a viable replenishment as it normally does not reach the groundwater. Geologists estimate that within 50 years, the pump system will be economically sustainable.
Aquaponics in Bustan, Egypt
Aquaponics is an agricultural and growing method that combines aquaculture and hydroponic cultivation, in order to obtain a symbiotic environment. Water from tanks for aquaculture is pumped into those hydroponic, so that the plants that grow there can filter it to draw nourishment, while extracting the waste substances produced by fish. The bio-filtered water can then be pumped back into the tanks for aquaculture and the cycle is resumed. At Bustan, the first commercial aquaponic plant in Egypt, young olive trees grow separated from the desert only by thin layers of glass: their cultivation uses 90 percent less water as compared to the conventional crop.
Extracting Water from the Air by the Air Drop
An interesting invention came out of a global competition from Sir James Dyson in 2012. Edward Linacre presented a device able to extract water from the air called AirDrop. That was inspired by the technique that beetles adopted in the desert. Even the driest air contains water (humidity). A machine draws air from the surface to underground, through pipes forming condensation, resulting in water directed towards the roots of the surrounding crops. The invention is now a working prototype.
The asparagus in China
There is no desert in this location, but in areas nearby, there is cultivation of crops specifically to control it. The researchers from Shanxi Academy of Agricultural Sciences conducted a successful three-year experiment with asparagus. The vegetable, also widely used in Chinese cuisine, was found to be a suitable windbreak in a project to combat desertification in Youyu, Shanxi Province. We were trying to plant vegetation capable of curbing the sand in the north and west of China; areas that are particularly threatened by the advance of deserts, facilitated by dry winds. Asparagus has shown its ability to withstand drought and cold, and has also been grown on barren land. They were able to yield 20 tons.
The Aflaj Oman
Oman is located in one of the driest areas in the world, where for centuries, water has been a priority. Symbolic of Omani ingenuity are the Aflaj, five of which have been recognized UNESCO World Heritage Sites. They are old ducts that still distribute 900 million cubic meters of water per year. Fields and gardens are watered for short periods of time, typically a half hour, and many villages have a sundial to mark the rounds of irrigation.