Introduction to hydroponics and hydroponic crops
Hydroponics It is a revolutionary method for growing plants that completely eliminates soil as a support and nutrition medium, moving towards modern, efficient, and sustainable agriculture. Its essence lies in the use of nutrient solutions that precisely provide all the essential elements for the development and growth of plants directly to their roots, using water and inert substrates as physical support.
The rise of hydroponics responds to the contemporary challenges of agriculture: population growth, scarcity of fertile land, water restrictions, environmental degradation, and the need to produce high-quality food in urban or inhospitable environments. Furthermore, this technique is becoming established as one of the pillars of sustainable agriculture and food sovereignty, integrating automation, monitoring and intelligent management technologies.
What is hydroponics and how does it work?
Hydroponics, whose term comes from the Greek hidro (water) and pride (work), encompasses a variety of methods in which plants grow in a system where the Water serves both as a means of hydration and as a source of nutrients, eliminating the need for soil. Essential nutrients for optimal plant development—nitrogen, potassium, phosphorus, calcium, magnesium, sulfur, iron, and other micronutrients—are dissolved in the water and delivered in a controlled manner directly to the roots.
In these systems, they are used inert substrates such as perlite, coconut fiber, rock wool, or clay to serve as a support, without providing nutrients themselves. In addition, hydroponic systems incorporate technology to monitor key parameters such as pH, electrical conductivity, oxygenation, and temperature, allowing for a absolute control of growing conditions and guaranteeing healthy, homogeneous harvests in less time.
Hydroponic systems can be installed in urban spaces, greenhouses, terraces, home gardens, and industrial-scale projects, adapting to the needs of each user and context.
Advantages of hydroponics over soil cultivation
- Efficient use of water resources: Hydroponic systems can reduce water consumption by up to 90% compared to traditional agriculture, thanks to recirculation and minimal leakage through evaporation or runoff.
- Use of space: It allows for growing crops in locations where soil is scarce, contaminated, or unsuitable (rooftops, walls, containers, urban areas). Vertical farming and tray stacking boost productivity per square meter.
- Total control over nutrients: Farmers can supply nutrients in a personalized and precise manner, avoiding deficiencies, excesses, and environmental contamination from leachates.
- Pest and disease reduction: By eliminating soil, the presence of pathogens and the incidence of typical soil-borne pests are minimized. Furthermore, the controlled environment reduces pesticide use and promotes cleaner production.
- Off-season harvests: Managing light, temperature, and humidity makes growing independent of the seasons, allowing for fresh produce year-round.
- Greater performance and homogeneity: Higher yields and more uniform products in size, flavor, and quality can be achieved by optimizing the growing cycle and the resources invested.
- Reducing the ecological footprint and circularity: Advanced systems leverage reused greywater and treated brines, promoting a circular economy through responsible water and nutrient management.
Disadvantages and challenges of hydroponic crops
- Significant initial investment: The cost of installing infrastructure, monitoring equipment, and automation is high compared to traditional agriculture.
- Technological dependency: The proper functioning of the system requires technical knowledge for parameter management and equipment maintenance.
- Error sensitivity: A nutrient or water shortage can quickly affect the entire crop. Furthermore, root diseases can spread easily due to the sharing of irrigation water.
- Electricity and energy continuity: Most systems require electrical power for pumps, sensors, lighting, or air conditioning.
- Waste management and recycling: If not managed properly, waste nutrient solutions or inert substrates can be generated, so it is essential to include recycling and treatment protocols.
Principles and fundamentals of hydroponics
- Controlled nutrients: In hydroponics, all the nutrients necessary for optimal plant growth are supplied from a specific aqueous solution, allowing both the composition and concentration of minerals and microelements to be regulated.
- Saving water: Water recirculation is standard, making the most of every drop and significantly reducing consumption compared to conventional farming.
- Space optimization: Since they do not require land, crops can be arranged in different configurations (vertical, horizontal, stacked), optimizing the use of available land and making farming viable in unexpected locations.
- Environmental control: Temperature, humidity, oxygenation, and lighting conditions are regulated and monitored, protecting crops from adverse external conditions and pests.
- Sustainability and reduction of chemical inputs: Hydroponics reduces dependence on fertilizers and pesticides, minimizes waste generation, and allows for the use of renewable water sources, such as treated gray water or reclaimed water.
Types of hydroponic systems
There are numerous hydroponic methods and technologies that have been developed and refined, adapting to different contexts, species, and production scales. The main systems are described below:
- Floating root system: The plants are placed on a plate or support floating in a nutrient solution. The roots remain submerged, and a bubbler system provides oxygen. Ideal for lettuce, chard and aromatic herbs due to its rapid growth.
- NFT (Nutrient Film Technique): A thin layer of nutrient solution is circulated through gutters or pipes, so that the roots have access to water and nutrients while remaining exposed to air above them. This system enhances oxygenation and is optimal for .
- Drip: A system of pipes and drippers distributes the nutrient solution in a regulated manner directly to the base of each plant. It adapts to open or closed growing systems.
- Ebb & Flow: Trays with inert substrate are periodically flooded with the nutrient solution, which is then drained, alternating periods of humidity and oxygenation of the roots. It is versatile and suitable for a wide range of applications. variety of plant species.
- Wick: The plants absorb the solution through wicks, without the need for pumps. It's simple, economical, and suitable for home gardening. low water requirement.
- Aeroponics: The roots are suspended in the air and regularly sprayed with a mist of oxygen-rich nutrient solution. This system promotes accelerated development and is very efficient in water, but it requires greater technical development.
- Inert substrates: They use materials such as perlite, clay, vermiculite, coconut fiber, or eSoil, which serve only as physical support, while nutrition comes from the aqueous solution.
Substrates and nutrient solutions in hydroponics
Los substrates in hydroponics They are inert materials (they do not provide nutrients and do not decompose) whose main function is to anchor and physically support the plant. The most common ones include:
- Perlite: expanded volcanic material, very light and porous.
- Rock wool: mineral fibers with great water and oxygen retention.
- Arlita or expanded clay: lightweight balls that facilitate aeration and drainage.
- Coir: It retains water very well, is renewable and sustainable.
- eSoil: a smart substrate developed in Sweden, composed of cellulose and conductive polymers, more sustainable than mineral wool and capable of electrically stimulating roots, accelerating growth.
- Vermiculite: good balance in water retention and aeration, ideal in mixtures.
La nutrient solution It must be adjusted to the specific needs of each species and stage of development, balancing macro and micronutrients, pH (around 5.5 – 6.5) and electrical conductivity.
Environmental control, automation, and innovation in hydroponics
One of the keys of the modern hydroponics is the use of technology to monitor and automate cultivation:
- Internet of Things (IoT) Sensors: They monitor variables such as temperature, humidity, nutrient levels, pH, and salinity in real time, facilitating precise management and resource optimization.
- Automation: Pumps, timers, LED lights, and programmed recirculation systems allow for minimal human intervention and reduced errors.
- Water recycling: Processes for purifying and reusing grey water or brine allow water management to be taken to a new level of sustainability.
- Telematic management: Large installations and vertical gardens have systems that can be controlled and monitored remotely.
- Development of smart substrates: Like eSoil, which integrates electrical conduction and allows root growth to be stimulated.
Areas of application of hydroponics
- Industrial and export agriculture: Large greenhouses use hydroponics to produce tomatoes, cucumbers, peppers, strawberries, and other fruits and vegetables with consistent quality and staggered harvests.
- Urban gardens: Hydroponics allows fresh food cultivation to be brought to cities, terraces, rooftops, and small spaces, increasing self-sufficiency and contributing to food sovereignty.
- Vertical gardens: It integrates architecture, design, and nature, allowing the cultivation of ornamental and edible plants on facades, walls, and baseboards, providing environmental and visual benefits.
- Research and education: Hydroponic systems are excellent teaching tools for schools, universities, and research centers in the areas of biology, agronomy, chemistry, and sustainability.
- Production under extreme conditions: It is possible to grow crops in desert regions, arid zones, or even in spacecraft, underground stations, and places where the soil is unproductive or contaminated.
- Food security and poverty reduction: Its implementation in urban, peri-urban, and hard-to-reach areas can contribute to nutrition, local job creation, and resilience to environmental crises.
Los hydroponic vertical gardens They represent the fusion of technology and nature, allowing for the installation of aesthetically pleasing and functional green walls in urban environments. These gardens are composed of vertical panels with pockets, compartments, or textile structures that support the plant cover.
The system is based on irrigation with nutrient solution Directly at the roots, with automatic control and recirculation of water and nutrients. Patented design innovations, such as the F+P system, integrate impermeable layers, corrosion-resistant materials, and telematic automation to reduce maintenance and protect infrastructure.
- Thermal and acoustic insulation for urban buildings.
- Improved air quality and contribution of biodiversity in cities.
li>Visual impact and emotional well-being in offices, homes and public spaces.
Comparison: Hydroponics vs. Traditional Soil Cultivation
- Soil independence: In soil, plants depend on fertility, composition, and health. In hydroponics, the substrate is merely a physical support, and nutrients are precisely dosed.
- Disease management: In soil, most pathogens, pests, and root diseases are present, while in hydroponics they are minimized, although they can spread rapidly if a diseased plant shares the solution with others.
- Production and crop cycle: Hydroponics allows for more frequent harvests, accelerating the growth cycle and providing greater quantity and quality of production.
- Resource consumption: In hydroponics, the savings in water and nutrients are significant, optimizing resources and reducing pollution.
- Environmental control: Traditional agriculture depends on climate, season, and soil; hydroponics allows for controlled, perennial crops, independent of the external environment.
- Flexibility and innovation: Hydroponics is ideal for integrating automation, sensors, and artificial intelligence, facilitating smart, precision agriculture.
Sustainable development and smart agriculture applied to hydroponics
In the current context of water scarcity, soil degradation and accelerated urbanization, hydroponics is key to the agriculture of the future and food resilience. By implementing sensors, IoT, and constant monitoring, we achieve:
- Optimize the use of inputs and reduce water and fertilizer consumption.
- Reduce the environmental footprint and waste generation.
- Generate accurate data for smart management of crops, anticipating risks of disease, nutritional deficiencies or water stress.
- Facilitate the integration of renewable energies (solar, wind) for the autonomous operation of the systems.
Use of reclaimed water and sustainability in hydroponics
The use of treated greywater, waste brine and reclaimed water It represents a breakthrough in sustainability. Research and projects such as Magtech, REGREEN, and membrane bioreactor technologies have demonstrated:
- Significant increase in the yield and quality of hydroponic crops.
- Reducing the water footprint and promoting circularity in water use, promoting the circular economy.
- Technical and agronomic viability in horticultural, fruit, and cotton production without compromising quality or food safety.
Water recycling and treatment allows for the recovery of essential nutrients, reducing dependence on industrial inputs and contributing to the long-term sustainability of agriculture.
Success stories and outstanding experiences in hydroponics
- Magtech Hydroponic Cotton: Efficiency has tripled compared to conventional methods, reducing water consumption by more than 75% and promoting the reuse of regenerated water resources.
- REGREEN urban garden in Barcelona: This urban pilot project demonstrates the viability of hydroponic farming using reclaimed water and is an international benchmark in metropolitan sustainability.
- Projar fruit trees and berries: Commercial implementations in fig, blueberry, and pome fruit using semi-hydroponic solutions, with 30% to 50% increases in productivity, reduced inputs, and increased harvest accessibility.
- Bioazul Richwater Technology: Membrane bioreactors facilitate nutrient recovery and safe irrigation with treated wastewater, verifying the equivalence of quality and performance with conventional systems.
Main factors for success in hydroponic crops
- Proper selection of hydroponic system: Depending on the type of crop, space, budget and technical experience.
- Monitoring and adjusting parameters: Controlling pH, conductivity, oxygenation, temperature and humidity is essential to achieve optimal and healthy production.
- Phytosanitary risk management: Increased cleanliness and prevention of root diseases through crop rotation, use of biological products, and root monitoring.
- Water quality: Use low-salinity water, free of toxic compounds, and, where possible, implement purification and reuse systems.
