Wednesday, October 5

Hydroponic crops: the advantages that your lettuce has never touched the ground


Who are the largest vegetable exporters in the world? The first country on the list is China, followed by the US and Germany. The next on the list will surprise you: Holland. Spain is in ninth position. The Netherlands exports twice as many tomatoes as Spain, and is close to the figures for Mexico, a country fifty times larger. As if that were not enough, the Netherlands is the world’s third largest exporter of fruit, just below Spain.

Not bad for a tiny country with gray skies and very little sunshine. How do they do that? With technology. The Netherlands is a leading country in smart farmingprecision agriculture, and a key to this revolution is hydroponics.

plants without soil

Hydroponics is a farming system that allows plants to grow in water where nutrients have been dissolved, without using soil. Instead, some kind of inert support material is used to keep the plants standing, such as perlite, basalt, or coconut fibre. Crops can be stacked vertically, in trays, requiring much less space. In fact, the cities of the future may become the centers of agricultural production, with “green skyscrapers” where crops are grown.

Although sometimes confused, hydroponics goes much further than drip irrigation and greenhouses, which is still the most common form of production. Unlike plants on land, water from hydroponics can be reclaimed and recycled. If you add artificial lighting with energy-saving LED light, crops grow much faster and allow you to obtain more harvests. The use of pesticides is not necessary either, because it is a closed and controlled environment.

The nutrients that dissolve in the irrigation water are nitrogen, potassium, phosphorus, calcium, magnesium, and sulfur, as well as other additional elements in smaller quantities. They can be obtained from various sources, from manure and fish or bird droppings, to synthetic fertilizers. Here is another advantage. It is estimated that 50% of the nitrogen from fertilizers in traditional agriculture never reaches the plants, and is lost through seepage or evaporation. This excess of fertilizers in the riverbeds creates dead zones like the Mar Menor in Spain or the Gulf of Mexico. On the contrary, in hydroponic crops not a single drop escapes.

The environmental impact is much lower than in traditional extensive agriculture, even when artificial lighting with LEDs is added, which compensates for the savings in water, fuel for tractors, harvesters, or nitrates such as fertilizers, the manufacture of which consumes enormous amounts of energy. As hydroponic crops adapt to any climate, they can be produced locally and save on emissions by transporting the products to other distant destinations. For example, in the case of the Netherlands, the main consumer of its fruits and vegetables is neighboring Germany.

Growing plants without soil is nothing new. The first mentions appear in the Natural History of Francis Bacon in 1627. The exact nutrient solution to feed the plants was described by German botanists at the end of the s. XIX. Today hydroponics is a common form of cultivation in laboratories, but the advances of recent years have made it the great promise to be able to feed the 10,000 million inhabitants that the planet will have in 2050.

In fact, today’s agriculture is one of the great threats to the environment. Agricultural macro-exploitations, deforestation, the disappearance of species, the transport of products, the depletion of the soil and, finally, the greenhouse effect emissions produced both by the activity itself and by the manufacture of synthetic fertilizers, cast doubt on sustainability. of the current agricultural model.

According to INE data, in Spain 80% of drinking water is dedicated to agriculture. Unfortunately, only half of the irrigation of the country are drip irrigated. A quarter of it is irrigated by flooding through ditches, and the rest by sprinkling, both methods with enormous consumption and losses of drinking water due to filtration and evaporation.

Some experts believe that hydroponics could completely replace traditional farming, just as the Roman plow replaced holes in the ground for planting seeds. Among its advantages are:

  • Higher yield: hydroponic crops produce between 3 and 10 times more food than conventional agriculture in the same space.
  • No herbicides or pesticides are necessary as the environment is controlled.
  • Water consumption 20 times less than conventional agriculture.
  • The plants grow in half the time.
  • More nutritious food: nutritional value increases as the time between planting and harvest decreases.
  • No contamination of soil and river water with fertilizers and pesticides.
  • Cultivation in any climate and any type of soil.

But not all are advantages, specifically, a high initial investment in technology and materials is necessary. However, the high yields make it easy to pay off. Above all, if the cost of environmental damage externalities of conventional agriculture is taken into account. In fact, the hydroponics market has grown fourfold in just six years.

hydroponics at home

Although temperature and humidity sensors, computer-controlled irrigation systems and air filters are used in precision agriculture, none of these are necessary to have our own hydroponic garden. There are starter kits which include the supports and the irrigation pump, but we can also build it ourselves with materials from any hardware store:

  • A 30 liter rectangular container with a tray that fits over it is needed.
  • An aquarium pump is installed that pumps the water from the container to the tray.
  • The plants are placed in the tray with coconut fiber or rock wool supports.
  • The container is filled with water with dissolved nutrients, which will have to be replaced every week.
  • The container with the plants is placed in a sunny spot or under LED grow lights.

Hydroponic crops are also part of Elon Musk’s plan to colonize Mars, although for all of the above, it makes much more sense to apply them to save Earth and feed its inhabitants.

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