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Organic hydroponics is a hydroponics culture system based on organic agriculture concepts that does not use synthetic inputs such as fertilizers or pesticides. In organic hydroponics, nutrient solutions are derived from plant and animal material or naturally mined substances. [1] Most studies on the topic have focused on the use of organic fertilizer.
There is increased consumer interest in organic hydroponics, as the global organic market is expected to grow nearly 25% from 2017 to 2024. [2] Due to decreased use of nitrate based fertilizers, nitrate levels in organic soil-based crops found to be lower than in conventional crops. Furthermore, beneficial microbes have been found to induce resistance against soil and air-borne diseases, [3] and can outcompete harmful organisms to promote resilient systems. [4]
Organics also present some health benefits. Since soil-based organic agriculture uses less pesticides, it has lower toxic residues than plants grown with inorganic fertilizer by approximately 75%. [5] [6] While there is inconclusive research on whether it is more nutritious than conventional agriculture, a meta analysis of plant nutrition found that soil-grown organic food is higher in antioxidants. [6]
Organic hydroponic systems often have lower crop yields relative to conventional hydroponics. A 2001 study found that lettuce grown in organic solution yielded much less and grew at a significantly slower rate than lettuce grown in conventional solution. [1] Furthermore, organic hydroponic systems are prone to large pH fluctuations, with limited input products that can be used to balance them out. [4] In addition, organic hydroponics requires very high amounts of knowledge, experience, and investment compared with conventional agriculture. [7]
Successful use of organic fertilizers can be more difficult in hydroponic systems than in fields, where beneficial microbes in the soil help to break down organic fertilizer into nutrients that are usable by the plant. When grown in soilless substrates, organic fertilizers may not be readily broken down by microbes and can inhibit plant growth. [8]
When evaluating the effectiveness of organic fertilizer, it is important to keep in mind the huge difference in effectiveness between different types of fertilizers. Besides differences between types of fertilizers, the mineral content from batch to batch can vary widely due to the organic nature of the sources, and the different crop fertilizer needs. There are a number of promising sources for organic fertilizer.
Vermicompost leachate, or worm compost tea, makes a highly nutritious fertilizer if the food and animal waste used in its production are of high quality. Since it is already liquid, it can be easily added to hydroponic systems.[ citation needed ] Similarly, a study in Japan had positive results using treated food waste as fertilizer. This study used fish-based soluble fertilizer and corn steep liquor, which are byproducts of existing food production, with success. [8] A study from Thailand used a combination of waste molasses, distillery slop, and sugarcane leaves. [7] After testing different ratios of these mediums, the authors found a ratio that led to growth rates comparable to those of chemical fertilizer. [7]
These methods have the added ecological benefits of being less energy intensive than inorganic fertilizer production, while diverting food waste from landfills, where nutrients are not cycled and greenhouse gases are generated as waste breaks down. [8]
Organic certification of hydroponics has been a heavily contested topic in the agriculture industry. In the United States, which is the only country that allows hydroponic production to be certified "organic," there are no formal guidelines on organic hydroponics. In 2010, the National Organic Standards Board voted decisively against organic certification of hydroponic production. [9] In 2018, an NOSB vote to change the NOSB's 2010 recommendation failed. The USDA refused to implement the 2010 NOSB recommendation, so certification was left to the discretion of third party certifying agents. [10] In 2020 a coalition organic growers and organizations sued the US Department of Agriculture demanding that USDA follow the NOSB recommendation that hydroponic production not be certifiable. The court dismissed the suit [11] on the grounds that this determination is within the USDA's discretion.
Hydroponics and aeroponics are not allowed to be labeled and sold as organic in Canada, as they do not meet the minimum soil requirements. [12] Similarly, beginning 2021 under the revised European Union organic law, hydroponically grown crops cannot be certified organic in the EU as they are not produced in soil-based systems. [13]
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions. Terrestrial or aquatic plants may grow with their roots exposed to the nutritious liquid or the roots may be mechanically supported by an inert medium such as perlite, gravel, or other substrates.
A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from liming materials or other non-nutrient soil amendments. Many sources of fertilizer exist, both natural and industrially produced. For most modern agricultural practices, fertilization focuses on three main macro nutrients: nitrogen (N), phosphorus (P), and potassium (K) with occasional addition of supplements like rock flour for micronutrients. Farmers apply these fertilizers in a variety of ways: through dry or pelletized or liquid application processes, using large agricultural equipment or hand-tool methods.
Organic farming, also known as ecological farming or biological farming, is an agricultural system that uses fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. It originated early in the 20th century in reaction to rapidly changing farming practices. Certified organic agriculture accounts for 70 million hectares globally, with over half of that total in Australia. Biological pest control, mixed cropping, and the fostering of insect predators are encouraged. Organic standards are designed to allow the use of naturally-occurring substances while prohibiting or strictly limiting synthetic substances. For instance, naturally-occurring pesticides such as pyrethrin are permitted, while synthetic fertilizers and pesticides are generally prohibited. Synthetic substances that are allowed include, for example, copper sulfate, elemental sulfur, and veterinary drugs. Genetically modified organisms, nanomaterials, human sewage sludge, plant growth regulators, hormones, and antibiotic use in livestock husbandry are prohibited. Organic farming advocates claim advantages in sustainability, openness, self-sufficiency, autonomy and independence, health, food security, and food safety.
Good agricultural practice (GAP) is a certification system for agriculture, specifying procedures that must be implemented to create food for consumers or further processing that is safe and wholesome, using sustainable methods. While there are numerous competing definitions of what methods constitute good agricultural practice, there are several broadly accepted schemes that producers can adhere too.
Sustainable agriculture is farming in sustainable ways meeting society's present food and textile needs, without compromising the ability for current or future generations to meet their needs. It can be based on an understanding of ecosystem services. There are many methods to increase the sustainability of agriculture. When developing agriculture within sustainable food systems, it is important to develop flexible business process and farming practices. Agriculture has an enormous environmental footprint, playing a significant role in causing climate change, water scarcity, water pollution, land degradation, deforestation and other processes; it is simultaneously causing environmental changes and being impacted by these changes. Sustainable agriculture consists of environment friendly methods of farming that allow the production of crops or livestock without damage to human or natural systems. It involves preventing adverse effects to soil, water, biodiversity, surrounding or downstream resources—as well as to those working or living on the farm or in neighboring areas. Elements of sustainable agriculture can include permaculture, agroforestry, mixed farming, multiple cropping, and crop rotation.
Aquaponics is a food production system that couples aquaculture with hydroponics whereby the nutrient-rich aquaculture water is fed to hydroponically grown plants.
Aeroponics is the process of cultivating plants in an air or mist environment, eliminating the need for soil or an aggregate medium. The term "aeroponic" originates from the Greek words aer ("air") and ponos ("work"). It falls under the category of hydroponics, as water is employed in aeroponics to deliver nutrients to the plants.
Organic fertilizers are fertilizers that are naturally produced. Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include all animal waste including meat processing waste, manure, slurry, and guano; plus plant based fertilizers such as compost; and biosolids. Inorganic "organic fertilizers" include minerals and ash. The organic-mess refers to the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture, not whether the fertilizer consists of organic compounds.
Organopónicos or organoponics is a system of urban agriculture using organic gardens. It originated in Cuba and is still mostly focused there. It often consists of low-level concrete walls filled with organic matter and soil, with lines of drip irrigation laid on the surface of the growing media. Organopónicos is a labour-intensive form of local agriculture.
Vertical farming is the practice of growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques such as hydroponics, aquaponics, and aeroponics. Some common choices of structures to house vertical farming systems include buildings, shipping containers, tunnels, and abandoned mine shafts. As of 2020, there is the equivalent of about 30 ha of operational vertical farmland in the world.
Deep water culture (DWC) is a hydroponic method of plant production by means of suspending the plant roots in a solution of nutrient-rich, oxygenated water. Also known as deep flow technique (DFT), floating raft technology (FRT), or raceway, this method uses a rectangular tank less than one foot deep filled with a nutrient-rich solution with plants floating in Styrofoam boards on top. This method of floating the boards on the nutrient solution creates a near friction-less conveyor belt of floating rafts. DWC, along with nutrient film technique (NFT), and aggregate culture, is considered to be one of the most common hydroponic systems used today. Typically, DWC is used to grow short-term, non-fruiting crops such as leafy greens and herbs. DWC was invented accidentally in 1998 by a legacy cannabis grower who goes by the name of “Snype”. This occurred because “Snype” and his (unnamed) associate had to take a trip to Amsterdam and needed a way to feed their cannabis crop while they were away. They built nutrient and water reservoirs that would keep the plants thoroughly fed in their absence, and thusly the DWC system was born. They revised this system in 2010 to create RDWC. The large volume of water helps mitigate rapid changes in temperature, pH, electrical conductivity (EC), and nutrient solution composition.
Controlled-environment agriculture (CEA) -- which includes indoor agriculture (IA) and vertical farming—is a technology-based approach toward food production. The aim of CEA is to provide protection from the outdoor elements and maintain optimal growing conditions throughout the development of the crop. Production takes place within an enclosed growing structure such as a greenhouse or plant factory.
Organic coffee is coffee produced without the aid of artificial chemical substances, such as certain additives or some pesticides and herbicides.
Intensive crop farming is a modern industrialized form of crop farming. Intensive crop farming's methods include innovation in agricultural machinery, farming methods, genetic engineering technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, patent protection of genetic information, and global trade. These methods are widespread in developed nations.
Agricultural pollution refers to biotic and abiotic byproducts of farming practices that result in contamination or degradation of the environment and surrounding ecosystems, and/or cause injury to humans and their economic interests. The pollution may come from a variety of sources, ranging from point source water pollution to more diffuse, landscape-level causes, also known as non-point source pollution and air pollution. Once in the environment these pollutants can have both direct effects in surrounding ecosystems, i.e. killing local wildlife or contaminating drinking water, and downstream effects such as dead zones caused by agricultural runoff is concentrated in large water bodies.
Soil management is the application of operations, practices, and treatments to protect soil and enhance its performance. It includes soil conservation, soil amendment, and optimal soil health. In agriculture, some amount of soil management is needed both in nonorganic and organic types to prevent agricultural land from becoming poorly productive over decades. Organic farming in particular emphasizes optimal soil management, because it uses soil health as the exclusive or nearly exclusive source of its fertilization and pest control.
Reuse of human excreta is the safe, beneficial use of treated human excreta after applying suitable treatment steps and risk management approaches that are customized for the intended reuse application. Beneficial uses of the treated excreta may focus on using the plant-available nutrients that are contained in the treated excreta. They may also make use of the organic matter and energy contained in the excreta. To a lesser extent, reuse of the excreta's water content might also take place, although this is better known as water reclamation from municipal wastewater. The intended reuse applications for the nutrient content may include: soil conditioner or fertilizer in agriculture or horticultural activities. Other reuse applications, which focus more on the organic matter content of the excreta, include use as a fuel source or as an energy source in the form of biogas.
Vermiponics is a soil-less growing technique that combines hydroponics with vermiculture by utilizing diluted wormbin leachate as the nutrient solution as opposed to the use of fish waste or the addition of manufactured chemicals to provide the nutrients.
Anthroponics is a type of hydroponics system that uses human waste like urine as the source of nutrients for the cultivated plants. In general, the human urine or mixed waste is collected and stored for a period of time, before being applied either directly or passed through a biofilter before reaching the plants. As a form of organic hydroponics, anthroponics combines elements of both hydroponics and aquaponics systems.
The Kratky method is a passive hydroponic technique for growing plants suspended above a reservoir of nutrient-rich water. Because it is a non-circulating technique, no additional inputs of water or nutrients are needed after the original application, and no electricity, pumps, or water and oxygen circulation systems are required. The Kratky method has applications both for commercial food production and as a small-scale and low-maintenance technique for home growers. It has been described as "the simplest hydroponic system."
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