Hydroponic crops have been an option given the limitations of suitable soils for planting, with which a greater use of space has been achieved and control of the factors of humidity, pH, oxygenation and the nutrients that plants require for their growth, for so we invite you to continue reading this article so you can learn more about this topic.
Hydroponic Crops
Hydroponic cultivation is a planting technique that is completely separated from the soil to grow food, since it is necessary to avoid the traditional drawbacks of regular cultivation, in addition to the obligation to use pesticides. In this way, the hydroponic garden will work with the roots in the elimination and with the different bases that can start from the bark to the foam, to this is added the water that this time is accompanied by important nutrients so that the crops.
There is the procedure that is based solely on the water and nutrients that the crops require, such as deep water crops, in this last model it is one of the cheapest and easiest to carry out at home, since the roots are fixed in a oxygenated solution with water and nutrients. There are also procedures based on a solid medium support, where you can choose from many alternatives, such as those with a substrate of biological origin, such as bark or moss, or even non-biological ones such as foam or sand.
General Features and Benefits
When we use this planting technique, the roots receive a set of nutrients such as phosphorus, nitrogen, potassium, zinc, iron, calcium, among others dissolved in the water for their correct development. In addition, this solution has all the essential chemical elements for the proper development of the plant. In this way, it can be said that the plant can grow only in mineral solution or in an inert medium, such as gravel, perlite or sand.
As for the general benefits: it favors planting in buildings and homes, as well as in areas where there is not much space. Planting time is relatively shorter than in traditional agriculture because the roots are in direct contact with the nutrients and produce exceptional stem, leaf and fruit growth. Less labor is needed as the land does not need to be cultivated. There is no problem of soil erosion as occurs with traditional crops, in addition to the fact that fertilizers are not applied.
Types of Hydroponic Crops
This interesting planting technique, which has been developed in different ways throughout the planet, in a large number of areas that can be thought of, such as commercial and productive. With this procedure, the main thing that is sought to obtain is a greater quantity of vegetable and fruit species, including some tubers and flowers. For this reason, in the following points we will be giving an explanation of the most used types of hydroponic crops:
Cultivation with Recirculating System
It is a system in which the flow of nutrients can be adjusted according to the wishes of the gardener, that is, frequent or interrupted. There are several models within this system, but the best known is TPN or NFT, where the flora or vegetation develops in rectangular opaque plastic gutters, so that light does not pass through them and prevents the development of algae in the solution. nutritious and also promotes a dark environment to facilitate root development.
The letter P of the acronym TPN, refers to the fact that the depth of the liquid that the roots absorb is very shallow, thus being able to supply oxygen more efficiently. In the case of NFT, the nutrient solution is supplied to the plants discontinuously, forming a very thin layer at the bottom of the gutter from which the plants absorb mineral water and oxygen. After a period of use (7-10 days), the nutrient solution is discarded and replaced with a new one.
Nutrients circulate in the area below the channels and the plants are located on top or in the perforated removable cover and their root system reaches the bottom of the channel, where it is bathed by the circulating nutrient solution and provides water, minerals and oxygen. . The solution flows intermittently: 10 minutes with nutrient flow and 5 minutes without nutrient flow in the hydroponic system. Since the nutrient solution is aerated, oxygen is supplied to the root system while the nutrient solution flows. The circulation ratio varies during the cycle of the system.
Tips
To use this type of hydroponics, the following advice is usually given: small plants do not need support, but large ones do. The tracks on which they will be located must have a dimension of 35 × 30 cm each row of 10 meters. In turn, it must have a 4% slope so that the nutrients flow by gravity along it, in such a way that nutrients are supplied from the upper end of the channels to the other end, where the nutrient tank and the nutrient solution can be aerated and recirculated.
The flow rate of the nutrient solution must be adjusted so that it is 1,5 liters / minute in each gutter, the adjustment must begin on the sides of the installation, leaving the central channels last. The nutrient solution is used for 6 days with daily correction of pH and electrical conductivity, adding water to correct the latter. On the seventh day, the water must pass through the gutters to wash them and remove the crystals that have formed in the root system, then a new solution is provided. In this system, the constant supply of electrical energy is vital because when it is lacking, the plants can die.
Advantages and disadvantages
Its advantages are: being able to add insecticides and fungicides to the nutrient solution. Any mistakes made in preparing the nutrient solution can be quickly corrected. There is no decrease in water due to evaporation from the surface of the gutter, it is reduced to perspiration and each day the volume of the nutrient solution must be completed and the pH and electrical conductivity measured and restored if necessary. The need to remove infested substrates is avoided, only the gutter is disinfected, which is easy and relatively inexpensive.
However, it can also be noted that this model of the system can present some disadvantages when using them, among which we have that, within the set of channels, large amounts of ethylene (C2H4) produced by the root system are developed, when This does not meet with a quality and constant supply of oxygen, which can generate the situation known as senescence, or old age before the time in all the roots.
Cultivation with Stationary Nutrient Solution System
This system is a variant where the plants are supported by a 5 cm thick anime, which allows them to float, with holes that are conveniently separated according to the plant to grow. The exposed roots of the plants are passed through these holes to put them in contact with the nutrient solution and to be able to absorb mineral water and oxygen. The roots of the plants must be well ventilated, so they must be aerated frequently (6 times a day) manually or with the help of a small aquarium motor with its diffuser.
Council for Nutrient Switching
After a certain time of use of the nutrient solution (7-10 days), it is removed, and the container is filled with a new or fresh solution. In this system, the exposed roots are always in contact with the nutrient solution, so it is necessary to supply oxygen, since its diffusion in the water is very slow and is influenced by temperature. It should be noted that oxygen is inversely proportional to temperature, let's say the higher the temperature of the nutrient solution, the lower its O2 content and vice versa.
It is important to take care of the air chamber and that its thickness is related to the development of the roots of the plants, since it is a source of O2 that, by diffusing all the nutrients involved, helps to supply the roots of the plants. In turn, keep in mind that initially if it is 1 cm thick, as the plant develops over time it becomes 3 cm, later it can increase to about 6 cm and, finally, reach a level of 10 cm.
Variants
There are two variants of this system: individualized and non-individualized plant grouping. In both cases there should be a support for the plant stem at the top and then an air chamber, then the nutrient solution at the bottom with the ventilation system. The first could use plastic tubs with a capacity of 18 liters or plastic tubs with a capacity of 8 liters (both opaque to prevent the passage of light) and 25 cm high, connected by the ventilation system.
In this first version of the system, it must be kept in mind that the bubbles must be very small to increase the solubility of oxygen in the nutrient solution. They must be changed every 7 or 10 days and during use it is necessary to recover the water lost through perspiration. Aeration can be done using an aquarium pump, which is connected to a timer on one side and an air bubble diffuser on the other. The pump runs 3-5 times a day for 5 minutes.
A wooden box (1 mx 1 mx 35 to 40 cm high) lined internally with plastic can be used to prevent loss of the nutrient solution, whose volume must be in accordance with the pump or compressor that will supply the air. The branched aeration system is placed on the polyethylene and on top of the nutrient solution, then the air chamber and finally the cover where the plants with bare roots are supported.
Cultivation with Organic Substances System
In this technique, all kinds of compounds of vegetable or fruit origin can be used, among which we can cite examples such as rice husks or husks and a mixture of coconut fiber with sawdust (50/50% v / v), which can be called as light organic substances as well. Coconut fibers and sawdust are products for grinding the mesocarp and exocarp of the coconut, and rice hulls are a by-product of rice processing (threshing).
Rice husks
This system needs a fermentation process, which can last between 2 to 3 weeks, in addition to cleaning with a large amount of water for 1 week, before use. It can be mentioned that it has a low decomposition intensity due to its high silica content. It is light and its main cost is transportation. On the other hand, it incorporates good drainage and good aeration, but low moisture retention. It is used in mixtures to increase aeration in them. It supplies silica to plants to which it confers protection against fungi (basically leaves).
Sawdust and coconut fiber
The use of these elements gives the system a good ability to store water and therefore little aeration. Coconut fiber, on the other hand, does not store water well and helps aerate the soil. For vegetation that requires a medium with a proper balance of water and air, a mixture of 30% coconut sawdust, 30% coconut fiber and 40% rice hulls can be used. Sawdust and coconut fiber have tannins that need to be fermented and washed before use, because if they are not done right, the crops will perform poorly.
Cultivation with Inorganic Substance Systems
Another of the modalities of substrates or substances that can be used in hydroponic crops are all those inorganic elements that can facilitate the development and subsequent production of the planted vegetation. In most cases, elements such as: sand, which does not matter if it comes from the beaches of a river or the sea and, on the other hand, gravel, which is a set of non-porous stones that They are usually found on the banks of rivers. Next, we will explain each of them in more detail.
Arena
In this first case, their granulometry or size must be between 0,2 and 20 mm in diameter, they must not contain bicarbonate (neither calcium Ca (HCO3) 2 nor magnesium Mg (HCO3) 2, nor calcium carbonates CaCO3 nor contain magnesium MgCO3) . On the other hand, it can be pointed out that sand has high capillarity due to the presence of micropores (less than 20 micrometers in diameter) that distribute the nutrient solution horizontally and vertically (three-dimensionally).
records
These are boulder clasts that are usually found on the banks of rivers. Their size or granulometry varies from 0,3 to 20 mm in diameter, they must be hard enough not to break. Due to the almost exclusive presence of macropores (more than 20 micrometers in diameter), it does not have capillarity, so it distributes the nutrient solution vertically from top to bottom or by sub-irrigation from bottom to top, this is how it should be watered with this grain size.
On the other hand, the macropores that can indicate the existence of low humidity, due to the fact that the nutritive elements are retained in the joints of the large rocks, for which the irrigation by sub-irrigation must be more frequent. The use of this element that has a non-organic origin with a diameter of 5 to 10 mm reduces the frequency of irrigation since it favors moisture retention. Avoid the use of gravel containing carbonates or bicarbonates of calcium (Ca) and/or magnesium (Mg).
Crops with Aeroponics
It is a modern class of hydroponic cultivation, in which the root system of the vegetation is suspended in the air and intermittently watered by a mist composed of the nutrients they need. The small drops that this form of irrigation has adhere to the surface of the root, providing water and minerals, in addition to this, they can provide the required oxygen. Therefore, it is an environment saturated with humidity where there is no substrate.
In addition, it can be said that aeroponics allows more harvests in a shorter period of time, due to the constant contact with oxygen, water and minerals and, consequently, a stronger development of the roots. In this particular class of hydroponic crops, you can see two models used, which provide the plant with water, minerals and oxygen under pressure. These are known as: low pressure and high pressure.
Low pressure
In this system, the droplets are larger and therefore carry less oxygen. The reservoir where the nutrients are located is under the plants, inside the root growth chamber and it is possible that when the roots grow a lot, they can enter it. The lid of the root growth chamber container supports the plant stems, surrounded by foam rubber, which seals the space and prevents moisture loss through it.
High pressure
In this system, the nutrient tank is separate from, but adjacent to, the plant root growth chamber. The pump is at high pressure and the sprayers create a mist of 10-30 micron droplets that sprays the roots for 1-5 seconds and stops spraying for 3-5 minutes. There is also a 1-minute spray and a 4-5 minute break. During the rest, it will be possible to observe that the vegetation absorbs water, nutrients and oxygen.
Tips for cultivation
The electrical energy should not fail, since the plants would die immediately due to the lack of oxygen and water in the roots. In addition, beneficial microorganisms should not be lacking in the roots of the plants with which it has symbiosis and help them absorb nutrients more easily. On the other hand, the fertilizers used must be completely soluble, they are generally powders, which allows a completely homogeneous liquid to be obtained during their dilution.
Also, the recommendation should be made that, if the vegetation to be planted is large, it is necessary to place a means of support by which they will be held in the air, usually by means of a rope. In turn, it is often mentioned that it is a type of hydroponic crops that does not require much water and nutrients. Even so, it is necessary that any vegetation must receive enough light to encourage its growth, usually about eight hours.
Depending on the size of the vegetation, the nutrients to be supplied must be changed every week in the low pressure model, but in the case of high pressure it can be changed at the end of the crop cycle. The nutrient solution must pass through a filter before being sprayed. Similarly, in both types of models, they must work perfectly for a long and continuous period of time, that is, the full 24 hours throughout the year.
Crops with Aquaponics
It is a kind of novel cultivation in which fish farming is combined with hydroponic cultivation of vegetation. Of course, both crops are physically separated, however, thanks to the connection between the two, they can benefit from the nutrients that recirculate in the medium. It can be noted that the first modern implementation of this system occurred in the Virgin Islands in the 90s. But there are antecedents carried out by the ancient Chinese and Inca civilizations.
How it is performed
The solution obtained from the fish is filtered to eliminate its excrements, to transform the ammonia (NH3) produced by the animal into nitrites (NO2) and finally, to convert the nitrites into nitrates (NO3). Ammonia is toxic to fish and also to plants, while the nitrates contained in nitrates are not. It can even be mentioned that it provides nitrogen to plants.
It can be mentioned that the animals must be raised in plastic containers with a capacity of 1300 gallons to avoid the proliferation of algae and lower temperatures. In addition, it must be recognized that the water to be used with the fish must have the following properties: It must not contain chlorine because it is toxic to them. It must have a pH of 7. The temperature varies between 22 and 32 ° C depending on the species of fish or animal, dissolved Oxygen between 4 and 9 ml / l. Low Nitrates (NO3) from 1,5 to 200 (mg/l) depending on the fish.
Tips for these hydroponic crops
The number of fish to be reared depends on the total volume of the tanks and the feed to be used daily will depend on the size and number of fish per tank or per cubic meter of water. The ratio between the volume of water used by fish and that used by plants is 1 m2 of fish / 2 m2 of plants. Fertilizers are generally not used because it is a biological system since the essential elements of the plants come from the transformation of the faeces, urine and food not consumed by the fish transformed by the biofilters into nutrients for the plants.
Crops with Green Forage (FVH)
It is a method of producing plant biomass (leaves and roots of seedlings) with a height of 25-30 cm, forms a kind of white «pillow» of mixed roots of high health (harmless) and nutritional quality (including high protein content). / amino acids and vitamin E). It is used in the production of hydroponic seedlings in large quantities that can be fed to all types of domestic or commercial animals: pigs, cattle, horses, chickens, goats, fish, changing a portion of balanced feed.
It is made very quickly (8 to 10 days) from high quality (90 to 95% high germination) Poaceae or grass (eg corn) seeds. It requires very simple greenhouses with a high percentage of kilograms of fresh HGF per square meter (75-105 kg of fresh green factor per square meter of greenhouse per day) since it is planted in 5 vertical levels separated vertically 35 cm. Due to the daily harvest / seed recycling that can be done 365 days a year, it is highly productive over time.
How are Hydroponic Crops made?
Knowing what are the different kinds of hydroponic crops that exist, it is time to think about the possibility of making one in an artisanal or homemade way, you can make use of new materials obtained in the markets or use all the elements that are found in the home to make use of recycling. Next, we will mention the materials you need and the other procedures that must be carried out to carry out this ecological undertaking.
Materials
To build one of these crops is very simple and easy to assemble, it is necessary to find the following materials: 2 plastic buckets with a difference in capacity of 1 liter each, that is, the first 10 liters and the second 9 liters. In addition, a substrate for hydroponic cultivation (coconut, expanded clay or perlite) is required. Submersible drainage sump pump. Tube oxygenator for the pump. Two robust plastic cups. Irrigation tubes. Automatic irrigation timer, as long as it is necessary.
Material
The only tool you can buy in theory is the submersible pump, but if you have small pumps for water it is enough, even if they have to develop a power of 4/30 W, otherwise the jet and the flow would be very abundant, the tools are easily recyclable. The two plastic buckets can be, for example, two metal or paint buckets. The important thing is that one of the two cubes is bigger, that it contains the other and that both are not transparent to prevent light from entering the interior of the container, but you could also paint them in dark tones if you prefer.
Drill a few holes in the small cube with a drill. Now you need to fill it with expanded clay. With the largest bucket you will need to fill in at least 4 gallons of water. Then insert the immersion pump into water, after placing the oxygenation tube in the appropriate space. Warning: If you are using a pump, do not submerge it in water unless you are sure it will not be damaged. In any case, take the irrigation pipes and connect them to the pump.
Take the bucket with the expanded clay and create a space for the plastic cups. Before inserting the vessels into the clay, drill several holes for the future roots of the cultivated plant to pass through. In addition, the clay will also be made in the cups, until the roots of the plant are long enough to be removed later. Take the prepared cube with the glasses and the clay, previously drilled, and insert it into the larger one, until the second cube fits with the first. While blocking, let out the irrigation hoses and connect them to the top bucket.
In order for the tubes to rest on the vase at a height of 5/10 cm from the cups or glasses, it is enough to fix them with a simple wire on one side of the container, using it as a support. Irrigation hoses are relatively inexpensive, but any hose can also be used. However, keep in mind that the tube must be the exact size of the pump hole. If necessary, connect the pump to a timer and then to an outlet for an automated system.
We can conclude that it is an easier way to build this method of cultivation, although if you have the necessary expertise, you can undertake one of the most complex hydroponic crops there is. In the same way, they all achieve the same objective, which is a complex cycle without interruption, made up of buckets or containers that acquire nutrients from a tank, which then irrigate the vegetation and make the solution run through the substrate. to the starting container. Finally, it can be said that regardless of the kind of hydroponics you choose, remember that you will have an excellent medium to grow effectively and productively.
Factors to choose the Type of Crop
You should start with a system that is easy to build, easy to maintain, and affordable for you, then move on to a more complicated system. The size of the model must be taken into account, which determines the cost and time required for care. Have clear objectives, whether for domestic use or mixed consumption, that is, consumption and sale of certain products. As well as the availability and quality of water, fertilizers and seeds. Have a protected area, without trees, light, wind and rain. The area should receive at least 6 hours of light per day, preferably in the morning.
Use of Containers
In recent years, the use of containers has been promoted in the different methods of this crop, which generates exponentially higher yields, by only using 90% less water than that used in traditional planting. In addition, it can be noted that it is necessary to ensure that the supply of vital liquid passes through the same place every twelve minutes. In this way we will convert the crops into a portable farm.
On the other hand, statistically speaking, with the use of these elements it is possible to obtain the production of 4 to 6 thousand units harvested every 7 days, that is, 50 tons per year, which implies an increase of 80 times higher than traditional crops. . In general terms, it is a way of planting that is increasingly gaining fame and employment in various parts of the planet, reducing material costs and labor use, with the benefit of maximizing production.
What can be grown?
There is a wide variety of vegetation that can be planted from these hydroponic crops. For example, we have cases where there is an incredible and constant development such as the Ficus, the Pathos, the Philodendri or even the Dracena. Although you may also prefer to plant vegetation that produces flowers, for example Hibiscus is very suitable, as well as Saintpaulia or Spathiphyllum. However, if what you are looking for is to obtain a field with fruit plants, perhaps the best ones are strawberries.
As for succulents and bulbs, it is more difficult. In this case, the strong presence of water can create a severe rot that results in the death of the plant. Unsurprisingly, if a bulb is planted, it should never be in direct contact with water, even if it is rich in nutrients. They should be submerged and not much, just the basic roots. Similarly, in the case of vegetables, it is good to consult specialists or nurseries to choose the most suitable species.
If you want to do this independently, the chosen vegetable must be cleaned of the earth present at the roots, immersing the part in water at room temperature for a few hours. Then everything has to be placed in the specific container for this type of cultivation, provided with holes for drainage and filled with inert material such as expanded clay, useful for absorbing and releasing the greatest amount of nutrients that it requires. To finish, we will mention some vegetables used:
- Chard
- Spinach
- Artichokes
- Garlic
- Eggplants
- Onions
- Cucumbers
- Tomatoes
- Carrots
History of Hydroponic Cultures
The transcendental antecedents of this type of plantation go back to the hanging gardens in Mesopotamia and the floating gardens of China. People have used these techniques for thousands of years. Although the general theory behind hydroponics remains the same. However, the first modern reference to hydroponics dates back to 1936, when William Frederick Gericke first used this method for large-scale commercial experiments in growing tomatoes, lettuce, and other vegetables.
During his studies at the university, he was able to demonstrate that plants were able to complete their life cycle only with a combination of nutrients and water without the need to be planted in any land. This undoubtedly caused a lot of uncertainty because it contravened conventional planting methods, but the evidence of the growth of large tomato plants led to the management of a new term in the area known as hydroponics.
The shocking results of his experiments with tomatoes received a greater number of field investigations. Then, the University of California conducted another investigation, where the researchers discovered many benefits related to growing plants without soil. Thanks to these studies, it was decided to use it to provide vegetables in places with extreme conditions, that is, deserts and snowy mountains, later the use of this wonderful food production system became widespread.
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