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 in addition, the roots may be mechanically supported by an inert medium such as perlite, gravel, or other substrates.
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 growing plants in the air or mist environment without soil or an aggregate medium. The word "aeroponic" is derived from the Greek meanings of aer ("air") and ponos ("labour"). It is a subset of hydroponics, since water is used in aeroponics to transmit nutrients.
The National Organic Program (NOP) is the federal regulatory framework in the United States of America governing organic food. It is also the name of the United States Department of Agriculture (USDA) Agricultural Marketing Service (AMS) program responsible for administering and enforcing the regulatory framework. The core mission of the NOP is to protect the integrity of the USDA organic seal. The seal is used for products adhering to USDA standards that contain at least 95% organic ingredients.
Passive hydroponics, semi-hydroponics or passive subirrigation is a method of growing plants without soil, peat moss, or bark.
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.
Total dissolved solids (TDS) is a measure of the dissolved combined content of all inorganic and organic substances present in a liquid in molecular, ionized, or micro-granular suspended form. TDS are often measured in parts per million (ppm). TDS in water can be measured using a digital meter.
Root rot is a condition in which anoxic conditions in the soil or potting media around the roots of a plant cause them to rot. This occurs due to excessive standing water around the roots. It is found in both indoor and outdoor plants, although it is more common in indoor plants due to overwatering, heavy potting media, or containers with poor drainage. The leaves of plants experiencing root rot often yellow and die, and if allowed to continue, the condition can be fatal.
The conductivity factor (CF) of dissolved salts in a given solution is a measurement of conductivity. Using the electrical conductivity between two electrodes in a water solution, the level of dissolved solids in that solution can be measured. Measurements can then be used to dose the solution with the necessary nutrients in the case of hydroponics. Conductivity measurements are also used in ecology and environmental sciences to assess the level of nutrients in lakes and rivers. For a discussion of conductivity in this context, see Total dissolved solids.
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. 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.
Ebb and flow hydroponics is a form of hydroponics that is known for its simplicity, reliability of operation and low initial investment cost. Pots are filled with an inert medium which does not function like soil or contribute nutrition to the plants but which anchors the roots and functions as a temporary reserve of water and solvent mineral nutrients. The hydroponic solution alternately floods the system and is allowed to ebb away.
A grow box is a partially or completely enclosed system for raising plants indoors or in small areas. Grow boxes are used for a number of reasons, including lack of available outdoor space or the desire to grow vegetables, herbs or flowers during cold weather months. They can also help protect plants against pests or disease.
Nutrient film technique (NFT) is a hydroponic technique where in a very shallow stream of water containing all the dissolved nutrients required for plant growth is re-circulated past the bare roots of plants in a watertight gully, also known as channels.
The Hoagland solution is a hydroponic nutrient solution that was newly developed by Hoagland and Snyder in 1933, modified by Hoagland and Arnon in 1938, and revised by Arnon in 1950. It is one of the most popular artificial solution compositions for growing plants, in the scientific world at least, with more than 19,000 citations listed by Google Scholar. The Hoagland solution provides all essential elements for plant nutrition and is appropriate for supporting normal growth of a large variety of plant species.
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. Most studies on the topic have focused on the use of organic fertilizer.
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.
Hawthorne Gardening Company, formed in October 2014, is The Scotts Miracle-Gro Company's subsidiary for cannabis growers and one of the first major investments by a major United States corporation in the cannabis industry.
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."
