Pros and Cons of a New Cultivation Way

When did Vertical Farming Born?

The Vertical Farming concept was born in 2011 in a classroom at Columbia University (N.Y.C.). During a lesson, Professor Dickson Despommier challenged his students to find a way to produce food within the perimeter of the island of Manhattan. The students initially proposed to grow crops on the top of the skyscrapers, but even using all the roofs on the island would only cover 4% of the population’s food needs. So, a new idea was born: let’s cultivate inside buildings exploiting the vertical space. That was a breakthrough.

At that time, all the technology we needed to put this vision into practice already existed.

All around the world, we were practicing soilless cultivation, like hydroponic, to produce vegetables or small fruits in greenhouses. Also, we were able to modify internal temperature and humidity, and there were already some horticultural lights. We only needed to put these technologies together.

Since then, the number of so-called “vertical farms” has increased worldwide, from the U.S. to Japan, China, Singapore, South America, and Europe (source A.V.F.).

In the last few years, the know-how on this cultivation has increased exponentially, technologies have made production more and more efficient, and many different crops have been successfully cultivated.

Let us try to understand how these farms 4.0 work, analyzing the various components of vertical farming.

How Vertical Farms Work?

Climatic Cells

Wherever you want to build your vertical farm, it is necessary to create an insulated environment to maintain the desired level of climatic conditions like temperature, humidity, and ventilation. The fully closed environment should prevent also the entry of pests and diseases.

Cells are usually made of sandwich panels, but containers are also used to develop modular farms. Climatic cells can be installed practically anywhere, from buildings to boats, warehouses, schools, or in the back of a restaurant.

HVAC System

After the insulation, the HVAC system (Humidity Ventilation and Air Control) is the first and most crucial vertical farming “tool.” This system has to filter the incoming and outgoing air, creating the best possible environment for the crops.

In developing a vertical farm, it is necessary to design the HVAC system with great care in line with the cultivation space. From this derives the success of the cultivation, the productivity of the crops, and the level of operating costs related to energy consumption.

Cultivation Methods

The two principal soilless cultivation methods in vertical farming are hydroponic and aeroponic.

Hydroponic is the most common.

The history of hydroponics comes from ancient Babylonian gardens, and different ethnicities have practiced it. Even today in Myanmar, the local population cultivates on rafts resting on the water of Inle Lake.

Industrially, Dutch farmers have developed hydroponic methods for producing inside greenhouses, and even NASA has developed some prototypes to produce food in space.

The idea is simple: the plants are suspended above ground level thanks to various supports, letting water and nutrients flow through the roots, generating a semi-closed irrigation circuit. Plants get the exact amount of nutrients they need, and no water is wasted.

The aeroponic system is more recent. The principle is the same, but water and nutrients are sprayed directly on the roots of the plants suspended in the air. This method is sometimes preferred to avoid water stagnation and increase the roots’ oxygenation.

Lettuce grown in hydroponics- Vertical Farming Education

Cultivation System

In vertical farming, we have already seen various types of systems. The mobile panels of Skygreen (one of the first industrial vertical farms in the world), N.F.T., towers and the most common racks used in the majority of farms. Recently, an Italian start-up developed a new prototype that uses artificial intelligence to move plants inside a large vertical farm “cube” to make cultivation extraordinarily efficient.

Lights

Since we are talking about indoor cultivation, you will need agricultural lights to reproduce the solar radiation, especially the wavelength of red and blue (this is the way lights seem pink or purple).

L.E.D.s used in indoor farming today are very energy-efficient and can be used to cultivate different crops. Some L.E.D.s are so efficient that they allow modifying the spectrum and the light intensity when you need to switch crops or even to replicate sunset and sunrise, giving plants the best possible simulation of solar daily changes.

Led used for lettuce cultivation on Radix system – Vertical Farming Education

Cultivation Software

Vertical farmers use a different kind of software to control and manage climate conditions, irrigation flows, and lighting. Software, artificial intelligence, and I.O.T. is in continuous development, increasing the level of automation in all farming process.

Seeds and Substrates

Starting from seeds instead of small plants is the least expensive and most followed-preferred strategy. Also, you can control the whole production chain, from sowing to harvest.

The plants generally cultivated in vertical farming are leafy greens, microgreens, small fruits, cannabis, soybean, aromatic herbs, and edible flowers.

The substrates on which plants are grown exist in different shapes and textures, from peat to rock wool. The substrate must be chosen carefully according to the cultivation system, the chosen crops, and the irrigation flows. Usually, the choice goes towards organic substrates, which can be composted and do not generate solid waste.

Microgreens on an organic substrate –  Profarms

Other Tools

Depending on the project, farmers can use other tools and machineries, from germination rooms to refrigerators and machines, for packaging, storage, automatic seedling and harvesting.

Pros and Cons of Vertical Farming

As you may have understood, the pros of vertical farming are numerous:

–       Saving soil: in vertical farming, space is used very efficiently, which is essential to produce food for the growing world population without exploiting additional agricultural land. Soilless cultivations also avoid problems like overfertilization which causes water pollution worldwide (especially in monocultures).

–       Saving water: vertical farming is particularly water efficient. With our students, we have demonstrated to use of 90% less water than in field agriculture.

With some systems, you can recover the moisture from transpiration, reusing that to irrigate the plants.

–       (Vertical) Farm to Fork: the possibility to grow crops in a fully controlled environment allows to produce practically everywhere, from warehouses to schools, boats, or even on international space stations. Growing food inside or close to big cities is a good way to avoid substantial carbon emissions and transportation costs. Reducing the time from harvest to consumption is a great way to keep crops fresh, flavorful, and nutritious.

–       12 months production: the possibility of producing all year round regardless of the external climatic conditions allows cultivation in every part of the world with extraordinary continuity and safety.

–       Producing and saving antique crops: monocultures, monodiets, pesticides, and climate change is responsible for the reduction of the species and varieties grown in the world. Having the ability to set different climatic conditions allows you to recover varieties of crops abandoned because they are less productive or unsuitable for the use of pesticides.

–       Clean food: growing crops indoors permits cultivation without the risks of pests or diseases, so there is no need to use herbicides or pesticides.

–       Attractiveness: loss of interest in agricultural practices is common worldwide. The technology and futuristic feature of vertical farming attract younger farmers, overturning the statistic.

Cons

–       Energy consumption: the energy necessary for the HVAC system (which works 24h) and lighting has to be considered in the global scenario. Nevertheless, solar panels and batteries can reduce energy consumption and costs.

–       Crops selection: you can grow practically every crop indoors, but only certain varieties are profitable and most suitable for this system today.

References

https://www.wur.nl/en/research-results/research-institutes/plant-research/greenhouse-horticulture/show-greenhouse/protein-rich-crops-growing-soybean-in-vertical-farms.htm

 

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