5 months ago

Is hydroponic farming the future of food production?

Hydroponics, or soilless cultivation of plants in a nutrient solution, is a rapidly growing field of commercial and hobby food production. Is hydroponics really the future of agriculture?

Is hydroponic farming the future of food production?
Contents

What is hydroponics?

Hydroponics (hydroponic from Latin 'water working') is a soilless cultivation of plants on nutrient solutions of aqueous solutions of mineral salts, enabling plant production under controlled conditions. Hydroponic cultures are especially useful for growing vegetables, herbs and ornamental plants. Thanks to the possibility of climate control, hydroponic cultures can be established regardless of external climatic factors.

History of hydroponics

The Hanging Gardens of Babylon are believed to have been grown hydroponically. The ancient Mesoamerians also created systems that allowed the cultivation of plants thanks to chinampas. These were the tied roots of plants floating in the water.

On top of them, a lake silt rich in nutrients was placed. Plants planted for chinampas, overgrowing them, took water from the lake. According to the FAO, plants cultivated in this way yielded up to five times a year.

However, the official beginning of hydroponics is the publication of the first work on this subject in 1627. The author of the book is Francis Bacon, who addressed the issue of plant cultivation in his work "Sylca Sylvarum".

Also in the 17th century, the scientist V. van Helmont in his works expressed doubts about the ideas of Aristotle. Helmond put forward theories about the primacy of water and air in plant cultivation. He put forward the thesis that soil shows only the ability to absorb water that plants take up by their roots and that it is a nutrient for plants.

In the 18th century, the English physician J. Woodward was the first to cultivate plants without soil. He is famous for his experiment with the cultivation of mint, in which he proved that plants grew better in dirty water from the Thames than in distilled water. As a result of this experiment, he put forward the thesis that plants need the presence of substances derived from the soil for proper growth and tissue building.

The first hydroponic cultures were established in 1868 and their creator was the botanist Wilhelm Knop. Together with Julius von Sachs, he identified nitrogen, calcium, magnesium, phosphorus, potassium and iron. Knop was also a co-founder of the Knop solution used in hydroponics to this day. He also proved that in order to nourish a plant it is enough to create a soilless environment in which soil components constitute food.

In 1860, Sachs published the 'nutrient solution' formula for growing plants in water, which became the starting medium for further experiments with plant cultivation.

Macronutrient salts
KNO30.25 g/L
Ca(NO3)21.00 g/L
MgSO4•7H2O0.25 g/L
KH2PO40.25 g/L
Knop's four-salt mixture (1865)

In the twentieth century, Hoagland added additional elements to Knop's solution, creating a medium that ensures the proper growth of various plant species. Information about Hoagland's solution can be found in his publication from 1950 - The water-culture Method for Growing Plants without Soil.

Absorption of nutrients by plants in hydroponics
Plants obtain 3 nutrients from the air–carbon, hydrogen, and oxygen–and 13 nutrients from supplemented water: nitrogen, phosphorous, potassium, calcium, magnesium, sulfur, iron, manganese, copper, zinc, boron, chlorine, and molybdate.

Currently, William Frederick Gericke of UC Berkeley is considered the father of modern hydroponics. He experimented with many types of crops, obtaining higher and faster yields from plants grown hydroponically than in soil.

The share of hydroponic farms in total food production is still low. However, due to economic reasons, advancing technology and the possibility of growing plants, regardless of climatic conditions, the share of hydroponics in food production is growing every year.

Global market forecast for hydroponics. Source: researchandmarkets.com

Benefits of hydroponics

  1. The possibility of establishing crops in areas not suitable for soil cultivation, e.g. in desert and rocky areas.

    According to the United Nations, by 2050 over 70% of the population will live in cities. In order to shorten the delivery time and increase the availability of healthy food, municipal gardening is already developing. Hydroponic farms are set up not only on the roofs of residential buildings, but also in shipping containers or even underground.

    The first underground hydroponic farm was created 33 meters below the surface of London. The originators of the underground hydroponic cultivation are Richard Ballard and Steven Dring, who founded the company Zero Carbon Waste, which in 2015 became a certified farm with a negative carbon footprint.

    One of the first important successes of the hydroponic method was on Wake Island. From the 1930s, hydroponics was used to grow vegetables for airline passengers, because the island had no conditions for soil cultivation and the transport of fresh vegetables from other parts of the world was too expensive. In modern times, hydroponics is an intensively tested method by NASA that aims to grow plants on Mars.

    Hydroponic cultivation of plants offers the possibility of producing pet food in countries where there are no favorable conditions for growing. These properties were used by the United Nations Central Emergency Response Fund by building 79 hydroponic greenhouses in Namibia. Such crops make it possible for local farmers to feed their livestock.

  2. No restrictions in the field of plant rotation - any plants can be grown one after the other, also in monoculture, because there is no soil fatigue phenomenon.

    Plants compete with each other for nutrients, water and space as they grow. They often leave the soil with metabolic products that inhibit the growth and development of other plants and species. In a hydroponic growing system, plants receive as much food as they need.

    If there is an accumulation of harmful substances in the water with the nutrient solution, it can be cleaned using special filters or the nutrient solution can be replaced. Additionally, it eliminates problems with growing plants in monoculture.

  3. Higher yields thanks to denser sowing and faster plant growth and development. Concentration of production in a small space.

    According to FAO, by 2050 the number of people on earth will reach 9.8 billion. The World Bank points out that in order to feed such a population, it is necessary to increase food production by 70%. Such possibilities are offered by vertical agriculture, i.e. vertical cultivation of plants. Hydroponic plants require only 1/5 of the available space, because their roots are supplied with nutrients directly, so that their growth is not as intense as in field cultivation.

    The world's first hydroponic vertical farm - Sky Greens, was established in 2012 in Singapore.

    “The world’s natural resources cannot sustain the current footprint of agriculture, especially when it comes to animal feed. To reverse current trends, we need a heavily disruptive and resilient food production model. The report makes a persuasive case for insect and hydroponic farming to complement conventional farming.”

    Juergen Voegele, World Bank Vice President for Sustainable Development

    According to a World Bank report, hydroponic farms will contribute to the growth of healthy and uncontaminated food in the world.

  4. Lower contamination of products due to the non-use of pesticides and no uptake of heavy metals from the soil.

    According to the EWG's, more than 70% of conventionally grown fresh plant products contain pesticide residues.

    Hydroponics and a soilless system is about not using soil as a substrate for growing plants. According to FAO, the main advantage of such a system is the absence of weeds and soil pests.

    Another important aspect of hydroponic cultivation is the fact that soil absorbs remnants of protective agents and accumulates heavy metals that can penetrate into the tissues of plants grown there.

    The need to change the food production system is strong. The report of the World Economic Forum points to the need to produce healthy, chemical-free food. Food Action Allience (FAA) has produced a report to transform food systems into more sustainable, efficient and non-destructive planets. The New Vision for Agriculture report also assumes the creation of environmentally friendly farms that will produce healthy and wholesome food.

    Many hydroponic farms employ ecological methods of growing plants, using natural pesticides and organic fertilizers. However, due to strict international regulations regarding the classification of the activity as organic, it is difficult for them to obtain an organic farming certification. The regulations defining organic farming were established by the NOSB and USDA. According to these regulations, organic farming is defined primarily as holistic crops.

  5. Possibility of postponing flowering and fruiting outside the normal season.

    Hydroponic farms offer the ability to control plant growth and development with both climate and nutrient adjustments 365 days a year. This means that it is possible to control the processes taking place in plants that stimulate their flowering. In addition, thanks to technology, in closed rooms, we are able to adjust the length of the day and the spectrum of light to the current needs of plants.

    Light spectrum for plants. Blue light is essential for seedlings and young plants as it establishes a healthy root and stem structure. It prevents excessive stretching and distortion of the stems. Red light is most important during growth as it is absorbed by chlorophyll. Far-red are wavelengths useful in controlling plant flowering and increasing fruit yield. Source: bioslighting.com

    Hydroponics provides plants with exactly what they need in a given growth phase. Depending on the species grown, blue light can affect nutrient levels and the color of leaves, flowers or the plant as a whole. The higher ratio of red rays helps to stimulate leaf size and flowering.

    In hydroponic farms, plants are grown using full-spectrum LED lamps. Thanks to this, with the strategic use of illumination, you can maximize the growth and rate of photosynthesis without stressing the plants. The optimal length of light can accelerate plant growth by 250%.

    Many growers also experiment with breaking the dark cycle with bursts of red light to speed up the growth and flowering of plants.

  6. Elimination of heavy work.

    Hydroponic cultivation also means the elimination of heavy field work related to soil preparation, sowing, care, fertilization, protection against pests and diseases, and harvesting. Despite this, manpower costs for hydroponic farms are around 20-30%. Of course, they can be minimized. State-of-the-art hydroponic farms minimize labor costs through robotization and process automation.

    Automation is able to repeat many processes from sowing through harvesting to packaging the finished product. Robotics is also increasingly used to observe and monitor crops for pests.

    Large farms use drones to find a single diseased plant in the entire crop. It enables quick intervention and minimization of costs related to possible losses.

  7. Water saving.

    According to The World Bank and UNESCO, all over the world, 70% of water consumption is used in agricultural production.

    It is estimated that by 2050 the global agricultural need for water will increase by another 19%. Moreover, currently around 40% of food is grown in artificially irrigated areas. UNDESA estimates that by 2025 1.8 billion people will live in regions with extreme water scarcity. In turn, according to the World Resource Institute, by 2050 the demand for water will increase by 30%.

    Water stress by World Resource Institute
    Water stress country rankings data. Source: www.wri.org

    Growing hydroponically plants uses 90% less water than traditional cultivation. Less consumption is related to the fact that the water necessary for watering and nourishing the plants is supplied directly to the roots.

    In 2015, a new cultivation system was created - dryponic. Dryponic is the latest technology that allows the cultivation of plants with dry roots.

    Dryponic cultivation enables the elimination of algae growth on the plant roots and reduces plant contamination. It also allows for 95% less water consumption compared to conventional crops. Thanks to this technology, plants remain fresh until direct consumption ('farm-to-fork').

  8. The ability to control the root ball.

    Growing plants in a hydroponic system allows you to control the size and quality of the root system of each plant you grow. And thanks to the constant availability of nutrients, plants produce a much smaller root system than in conventional crops, and thus do not need to compete for space and macro micronutrients.

  9. Ecosystem protection.

    Hydroponic farms do not directly affect the surrounding natural environment. Due to this relationship, the possibility of contamination or degradation of the soil around the plantation is practically non-existent. Soilless cultivation in monoculture will not affect the sterilization of the soil.

    On the other hand, the introduction of vertical food crops does not expand the area of arable land, and thus there is no need to cut forests and destroy biodiversity. Also, using 90-95% less water will help conserve natural resources.

    Limiting the use of pesticides and artificial fertilizers does not pollute the soil and groundwater. And the proximity of urban farms or underground hydroponic farms in urban space reduces CO2 emissions to the atmosphere. The negative carbon footprint of the growing number of hydroponic farms is another important aspect of hydroponics.

    Contribution of each commodity to carbon footprint and food wastage. Source: FAO.org

Limiting the use of pesticides and artificial fertilizers does not pollute the soil and groundwater. And the proximity of urban farms or underground hydroponic farms in urban space reduces CO2 emissions to the atmosphere. The negative carbon footprint of the growing number of hydroponic farms is another important aspect of hydroponics.

Summary

Taking into account the risks associated with feeding 8.1 trillion people, hydroponics becomes a system that guarantees the intensification of production. Hydroponic cultures produce a larger, faster, healthier crop, rich in nutrients.

An additional advantage is that the hydroponic farm can function efficiently not only in city centers but also in the most unfavorable climatic zones.

Shortening the time of reaching the consumer is another undeniable advantage of this type of cultivation.

Minimal consumption of water, space, high efficiency, non-polluting the environment and biodiversity, and even negative CO2 balance make hydroponic farms a guarantee of providing food for future generations.

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