published on 20 September 2010 in energy
The problem of food
According to recent estimates made by the UNO, the global population will increase by 3 billion and a surface area as big as Brazil (109 hectares) will be required to feed these people. In fact the demand for food will increase about 70% compared to the current production and therefore new areas that can be cultivated will be necessary. At present 80% of the land that is available for agriculture is already utilized. The challenge of the future, therefore, will be to find surfaces that can be cultivated, to be able to feed the world population. It will be necessary to produce an ever-increasing amount of food, of a better quality, and in full respect of the environment. An increase in the production of food in the past 40 years, in fact, has had a very high price in terms of ecology, provoking a severe deterioration of the cultivated fields and an overall degradation of the environment. One of the challenges that humanity must overcome, is to find a correct balance between the production of food and respect of the environment.
The passage from “traditional agriculture” to “modern agriculture” has been marked by the green revolution. Approximately 50 years ago, in fact, agriculture came to a turning point: the traditional agricultural activities based on the cultivation of local products and manual labour of the farmers, in fact, was gradually replaced by a more technological and intensive agriculture, tied to industrial processes. This change coincided with the time when the developed countries began to look at the agricultural activities as a sector of a very promising development, even from an industrial point of view. With the green revolution, varieties of vegetable products with a high yield were introduced, and these replaced the numerous local varieties that were cultivated before, with the scope of increasing agricultural production. These new varieties of plants, known as “hybrids” are more receptive to nutrients, they ripen faster and can grow in all the seasons, thus allowing a number of harvests per year. Furthermore the heavy machinery has replaced human and animal labour, and the massive use of chemical fertilizers and pesticides (weed-killers and parasite-killers) has led to a further increase in the productivity. Polyculture farming, i.e. the production of a large variety of agricultural products, with the scope of directly satisfying the local needs of the agricultural population has been replaced by monoculture farming, i.e. the intensive cultivation of a single vegetable species. Today, therefore, farms are specialized in the production of a small number of cultures, produced in large amounts so as to have a consistent excess that is exported and forwarded to industrial production.
The other side of the coin
The Green Revolution has guaranteed food in the countries where intensive agriculture was widespread, but at a very high cost for the environment. Firstly, the massive use of chemical pesticides and chemical fertilizers has caused a serious degradation of the environment, has been harmful for the health of those employed in agriculture and has severely affected the world water resources. The new variety of cultures, introduced with the green revolution, are highly efficient in terms of yield per hectare, but are inefficient when compared with the amount of water used. Today approximately 70% of all the water taken from the rivers and the underground water reserves is spread out on 270 million hectares of cultivated fields that produce one third of the world food requirement. Furthermore high-yield plants require very deep tilling of the land, with machinery that destroys the structure of the soil. The cultivation of the new improved varieties and breeding of new breeds of livestock have led to the abandoning and extinction of a number of local and traditional varieties, provoking a remarkable decrease in agricultural biodiversity. Finally, even though agricultural productivity is very high, hunger is still widespread in many areas of the planet, because the green revolution has brought benefits only where the investments have been made, and where there are sufficient resources in terms of land and water to develop an intensive type of agriculture.
Strawberries on the tenth floor
The shortage of space for agriculture in the future, the population growth and progressive urbanization (in 2050 , 80% of the population will live in urban centres) all lead to one of the greatest challenges for man: the availability of food. In order to feed the global population it will not be sufficient to make the production lines more efficient, nor distribute food resources more fairly, nor modify the consumption, for example by decreasing the intake of meat. And so the idea of the vertical farms, was born, these should enable agriculture and animal breeding without using the land but developing in height, inside skyscrapers. The father of this new method of producing food is Dickinson Despommier, a Professor of Environmental Sciences at the Columbia University, who has been promoting vertical farming as an agricultural method that can be integrated in an urban context since 2000. The idea of cultivations in closed environments is not new: just think of the greenhouses, that enable us, today, to cultivate fruit and vegetables even when out of season. The novelty of the vertical farms is that they will be created in urban centres inside skyscrapers and buildings. It is calculated that a farm whose base is as big as a city block, and 30 floors high, can feed 10 thousand people! Architects and engineers, together with agronomists and biotechnologists, have been working since a long time at experiments on vertical growth of crops. Vertical farms are real agricultural farms, developed inside buildings, and created with the aim of a sustainable food production for the requirements of thousands of people, in an energetically independent, economic manner, and blending harmoniously into the urban environment. Vertical farms are provided with photovoltaic panels and wind blades to produce electricity, geothermal heat pumps to air-condition the environments, the production of biomass from the waste and reutilization and recycling of the waste materials and water, so that they are self-sufficient for energy, and they will reduce the environmental impact of agricultural activities to the lowest levels. Furthermore, by zeroing the distance between the area of production and consumption, the product costs are decreased, every hectare of urban soil occupied by vertical farms will produce the equivalent of 4-5 hectares of land cultivated in the open and an efficient seasonal crop rotation, and the total absence of pesticides, will guarantee the quality of the harvests.
Skyland, an Italian project
Skyland is the vertical farm designed by ENEA. It is a futuristic architectural project that integrates advanced engineering solutions and innovative materials and technologies, for sustainable food systems
The motto of Skyland is: 5 zeroes:
Zero pesticides: the closed and controlled environment, does not require use of pesticides for the cultivations.
Zero energy: a system of photovoltaic panels for electricity and a geothermal heat pump system for the air-conditioning, shall guarantee that all the energy that is used comes from renewable sources.
Zero waste: Skyland will use waste to produce energy, alternatively the waste will be recycled. Also the water will be suitably filtered and used again.
Zero kilometres: vertical farms promote food at kilometre zero, in fact the vertical farms include a farmer market where the agricultural products that are grown on the high floors are sold. The consequences can only be positive; a decrease in the use of fuel for transportation of the food supplies from the area of production to that of distribution, and a decrease in the sales price for the consumer, as a result of the short manufacturing process line.
Zero emissions: all the emissions into the air and water shall be filtered, to avoid pouring any polluting substances into the atmosphere.
Edited by Benedetta Palazzo