It is estimated that by 2050, 80 percent of the world’s population will live in cities. And the total population will increase to 9.2 billion, most of them in developing countries. Many experts believe that if strict restrictions are not adopted, mankind may face severe shortages of food and arable land, with many dire consequences, such as famine and ecological disasters. Scientists are therefore extensively seeking new directions for human development.
Vertical farming was first proposed by Dickson D. Despommier, an emeritus professor of microbiology and Public Health at Columbia University to study the population pressure and resource scarcity problems facing future agricultural development. Its main task is to solve the full utilization of resources and space to achieve the maximum yield per unit area. Despommier’s skyscraper-style vertical farm is just like a skyscraper. With a height of about 30 to 40 stories, each floor could be used for planting and raising various crops and livestock. Modern technology can be used to minimize waste and energy use and promote recycling. To this end, these farms will be equipped with glass walls, large solar panels, high-tech irrigation systems and incinerators for burning waste to produce energy. The farms will also be equipped with various monitoring systems to ensure that energy and water are in the right place and that temperatures are properly controlled. In short, a new model of agricultural development that makes full use of renewable resources and greenhouse technology to significantly increase agricultural yields and land use by conducting various agricultural production in a high-rise building. The vertical farm has a cylindrical shape, with each floor stacked like a chip. Each floor is an agricultural field and has a complex irrigation system. All crops will be grown in a controlled environment and checked for maturity using electronic eyes, and can be planted and harvested 365 days a year.
- Production will be uninterrupted throughout the year, unaffected by seasons and natural disasters. Vertical farms will grow crops on demand, and any crop can be grown anywhere, anytime, so people will not need to store food.
- Higheryield per unit. By using space efficiently, vertical farms can grow more food in a much smaller space than traditional farms.
- Consistent quality yield. Industrialized production results in more uniform harvested crops that are more in line with market standards.
- Shorter supply chain. Vertical farms are built in skyscrapers in the heart of cities, which means that crops produced in the city can be sold directly to city dwellers, shortening transportation distances and practices, saving transportation costs, keeping food fresh and reducing waste generated in the supply chain.
1. The input cost is too large and involves many aspects such as architectural design, engineering arrangement, agricultural operation and agronomic planning.
- Higher requirements for technical and managerial quality, traditional farmers will lose a place in the modern society.
- Larger electricity consumption. Vertical farms require greater electrical input than traditional greenhouse cultivation. Some data show that if we want to use vertical agriculture to replace the annual wheat production in the United States, the electricity needed for lighting alone is 8 times the total electricity produced by all power stations in the United States in a year, which obviously deviates from the original intention of green.
Although there are still many problems with the idea of vertical farms, the urgency of the food security issue and the great theoretical advantages still attract countries competing to try this new agricultural model. At present, there are prototypes of vertical farms in Singapore, Japan, Korea, the United States, Cuba, the Netherlands and China.
Singapore, Sky Greens
Singapore, a “garden city” country with 50% green space, produces only 7% of its crops domestically and imports most of its vegetables from neighboring countries. The system is also the world’s first hydraulic driven vertical farm. The vertical farm currently produces some of the most popular vegetables in the region, such as chard, milkweed, choy sum, kale and spinach. Because the vegetables are grown in a natural way, their quality is relatively high and their retail price is slightly higher than that of ordinary vegetables.
Sky Greens uses approximately 9-meter high A-shaped planting towers, each containing 38 layers of planting tanks that rotate slowly from bottom to top at a rate of 1 millimeter per second to ensure uniform levels of light, airflow and irrigation. The unique feature of the planting technology is that it does not use LEDs to simulate light, but direct sunlight. The entire system occupies only about 60 square feet and is enclosed by lightweight Plexiglas to create a greenhouse environment. The stepped arrangement ensures that all plants receive sufficient light. More subtly, the rotating system does not require additional electricity to power the system, but rather a unique water gravity system that allows the system to automatically collect rainwater, which is filtered and then fed into the irrigation system after powering the rotation.
AeroFarms is an American vertical farming company founded in 2004 and is one of the first explorers of the vertical farming model.
AeroFarms uses proprietary technology to produce leafy greens, allowing plants to grow in an indoor environment with no sunlight or soil at all. Instead, new technologies such as LED lighting, aeroponics and climate control are used to revolutionize existing growing techniques so that plant growing is no longer affected by inclement weather. Soilless cultivation technology, which eliminates soil pollution such as heavy metals; indoor safe and controlled environment, which eliminates the use of herbicides and pesticides and makes vegetables free from external
environmental pollution. Intelligent lighting solutions, nutrient rationing supply, pest management and data management greatly optimize the crop growth process and increase yields.
AeroFarms uses a mist cultivation system that uses a spraying device to atomize the nutrient solution into small droplets that are sprayed directly onto the plants. This technology uses 95 percent less water than traditional growing methods and can harvest approximately 700 fruits and vegetables in 10 to 14 days, compared to 30 to 45 days with traditional farming methods, and is 390 times more productive than growing plants in the field.
AeroFarms now has several indoor farms around the world, primarily for wholesale operations, with customers including restaurants, food companies and supermarkets. The average consumer can also shop for its own brand Dream Greens by making reservations online, and currently the main delivery area is still focused on the New York area.
Vancouver-based Alterrus Systems brings the first vertical farm to North America in the form of the VertiCrop. After the recent emergence of a green concept that became a reality, VertiCrop is now located on top of a parking lot in downtown Vancouver. The technology is based on hydroponics, which provides optimal artificial and natural light for plants by moving specially designed suspended trays through a delivery system. The design allows crops to grow healthily in a controlled and enclosed environment, completely free of herbicides and pesticides, and with yields 20 times those of ordinary field crops, requiring only 8% of the water needed for soil cultivation.
In a space of 50 feet x 75 feet, there are 120 shelves, each with 24 planting trays, and the food produced is equivalent to a 16-acre farm. Each shelf moves around the greenhouse in a computer-operated environment. Indoor temperature, lighting, fertilization, irrigation, etc. are all precisely controlled, and used water can also be recycled. The system is designed to provide maximum sunlight and precise nutrients for each plant.