What is hydroponic farming?
Controlled environment agriculture (also known as weather and climate-proof farming, or more commonly indoor vertical farming), is the production of plants in an indoor environment. While indoor farming is not a new phenomenon (greenhouses have been used for centuries), the more recent innovation of hydroponic farming breaks down the growing process even further by eliminating all unnecessary components of traditional farming. Thinking back to the process of photosynthesis learned in middle-school biology class, we can recall the core elements to plant growth as energy, nutrients, water and CO2. Controlled environment agriculture (CEA) follows this basic formula and does away with all unnecessary inputs that have become essential to our current agriculture system, such soil and pesticides. In the CEA process, conventional elements of traditional farming are substituted with artificial ones. Rather than from the sun, plants receive energy from LED lighting that is tailored specifically to the energy needs of the plants. Instead of using soil, seeds are planted in soil-free growth mediums such as coconut husk to provide the seedlings with a surface to attach its roots to. This soilless process minimizes the risk of invasion by bugs and weeds into the growth environment, ensuring a much more clean and simple process. These seedlings are sometimes placed into growth trays which are stacked upwards, instead of outwards, in a vertical racking system. The vertical integration of plants allows for farmers to optimize the total space usage of their growth area, making it possible for farmers to reduce their land use by up to 90-99% while also increasing productivity. Plants growing in vertical farms are fed essential nutrients either hydroponically, in which nutrient-infused water is fed to the plant roots which sit in a growth medium, or aeroponically, in which the plant roots dangle freely and are misted with the nutrient-infused water.
Why Hydroponics?
Humans are now up against a myriad of new demanding issues that are leading dramatic change to our global lifestyles: climate change, hazardous infectious diseases, increasing urbanization, and the depletion of natural resource deposits. Hydroponic farming has strong potential to mitigate the threats these issues pose to our agricultural system. Growing crops in near optimal conditions using controlled environment agriculture (CEA) technology is one of the biggest benefits of hydroponic farming. Crops grown indoors and hydroponically can be grown anywhere on earth at any time of the year, regardless of weather conditions, availability of cultivable land, or soil quality. Hydroponic farming has the potential to provide fresh, local food for areas with extreme droughts and low soil quality, such as in sub-Saharan Africa where access to leafy green vegetables is often limited.
Keeping crop production in a controlled environment enables trained scientists and advanced climate control technology to optimize the inputs of water, nutrients, and light fed to the plants. For example, sensors can measure the amount and nutrient content of the water that each plant transvaporates. This gives farmers insight into the amount of unused water and nutrients by the plants at each stage of the growth process. From this, farmers are able to ensure the maximum amount and highest quality of yields by optimizing the timing, quality, and amount of inputs to the plants. This technology, along with design features such as precise irrigation methods, helps CEA farmers reduce water waste exponentially: compared to traditional farms, hydroponic farms use up to 90% less water. Light inputs are also optimized to ensure maximal absorption by the plants and maximal yield outputs. Photosynthetic active radiation, or PAR, is a measurement of the amount of usable light (photons) delivered to different plants. The range between 400 and 600 nanometers represents the usable wavelengths of light energy for plants, though scientists have found that the peak of absorption is often at 440nm (blue light) and 660nm (red light). If the delivery of these optimal wavelengths of light are targeted, the amount of energy being delivered to the plants can be optimized by omitting the wavelengths of light that will not be absorbed by the plants. This is the reason for the purple-ish light often seen shining on plants in hydroponic farms. This is also the logic behind the color of greenhouses: the green glass ensures that green light does not pass through to the plants so they only receive the colors that they most readily absorb. Since LED lights are heavy energy users, optimizing the light delivered to plants to the maximum amount of light absorption helps limit wasted energy.
The modular design of vertical farms allows farmers to alter the layout of the plants to maximize space use and optimize ground space. Since vertical farms spread upwards instead of outwards on a horizontal plane, farmers are able to grow 3 to 10 times more crops in the same amount of space as conventional farms, depending on the specific layout. Ground space can be multiplied by stacking horizontal racks on top of each other. This same modular design also offers a highly efficient way to isolate diseased or dying crops with a quick and easy way to neutralize compromised plants. In a traditional farm that might cover many square miles of land, diseased crops are much more difficult to identify and take out of contact with the other crops in the field. As a business model, modular farming also enables a much more efficient growth process, where transferring and packaging plants can be completed without causing any disturbance to other crops. Finally, with the help of soil-less growing, this modular design allows growth space to be in constant use. In other words, no wait period is needed after harvesting a crop cycle before the next crops can be planted again. With the help of a constant stream of nutrient and light inputs that significantly reduces the crop cycle, this farming model can result in 7 to 14 times more growth cycles than traditional practices.
Another benefit of the secure indoor growing environment is the protection it provides the plants against harmful pests and microbial diseases. Traditional agriculture makes use of intense applications of herbicides and pesticides to shield crops from natural threats, though these chemicals have become under increasing scrutiny for the adverse effects they pose to humans and surrounding ecosystems. Pesticides often contaminate surface water, are toxic to many non-targeted insects, animals and plants, can eliminate positive and healthy soil microbes, and have been linked to breast cancer in humans. In the United States, more than 1 billion pounds of pesticides are used annually, 90% of which is used by the agriculture industry. The faster we can cut down on the amount of pesticides contaminating our food and environment, the better off our health and world will be.
Furthermore, pesticides have failed to make our agriculture industry completely resilient against invasive species. This past summer, a devastating swarm of locust pests descended upon East Africa, guzzling up the food supplies of up to 25 million people. Despite emergency applications of pesticides across the continent, nothing could stop these locusts from demolishing the year’s work of farmers and the precious food supply of millions of East-Africans. Farming indoors eliminates crop vulnerability to extreme circumstances such as these and more common, lower grade pest invasions alike.
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