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Review key Hydroponics: Soilless Agriculture, Systems & Plant Nutrient Science exam facts and rate your mastery to track revision.
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#1
Hydroponics is the technique of growing plants in water enriched with essential mineral nutrients without soil.
#2
The term "hydroponics" comes from the Greek words "hydro" (water) and "ponos" (labor), coined by William Gericke in 1929.
#3
German botanists Julius von Sachs and Wilhelm Knop established the scientific principles of hydroponics in the 1860s.
#4
Soil is not biologically mandatory for plants; it serves primarily as mechanical anchorage and a reservoir for minerals and water.
#5
Plants absorb nutrients as dissolved inorganic ions (such as nitrate, phosphate, and potassium) through root cell membranes.
#6
Hydroponic farming uses up to 90 percent less water than conventional agriculture because the nutrient solution is recirculated.
#7
Nutrient Film Technique (NFT) passes a continuous, shallow stream of water over roots held in sloping channels.
#8
Deep Water Culture (DWC) suspends plant roots directly into an aerated reservoir filled with nutrient-rich water.
#9
Aeroponics is an advanced variation where roots hang in an enclosed chamber and are misted periodically with nutrient droplets.
#10
Ebb and Flow (flood and drain) systems periodically submerge plant roots in nutrient solution before draining it away.
#11
Inert growing media used for mechanical root support include perlite, rockwool, vermiculite, and expanded clay pebbles (LECA).
#12
Cocopeat (coconut coir) is an organic, biodegradable soilless medium prized for excellent aeration and water retention.
#13
Electrical Conductivity (EC) measures the concentration of dissolved mineral salts in the hydroponic solution.
#14
Solution pH must be maintained between 5.5 and 6.5 to ensure optimal mineral solubility and prevent nutrient lockout.
#15
Dissolved oxygen must be actively pumped into nutrient reservoirs to support cellular respiration and prevent Pythium root rot.
#16
Primary macronutrients supplied in hydroponic formulas include nitrogen (N), phosphorus (P), potassium (K), calcium, and magnesium.
#17
Micronutrients essential in trace quantities include iron, manganese, zinc, boron, copper, and molybdenum.
#18
Hydroponic cultivation eliminates soil-borne pests, weeds, and pathogens, substantially reducing the need for chemical pesticides.
#19
Crops best suited for commercial hydroponics include leafy greens (lettuce, spinach), herbs, strawberries, tomatoes, and peppers.
#20
Combined with LED grow lights in vertical farms, hydroponics enables year-round indoor agriculture in dense urban environments.
Subject Specialist Commentary
Analytical perspective & practical exam advice from the Master10 academic board
Hydroponics is an agricultural method of cultivating crops directly in water enriched with dissolved mineral nutrients, completely bypassing natural soil. Coined from the Greek words for water and labor by William Gericke, the technique proves that soil is not biologically mandatory for plant development; it merely provides physical anchoring while roots absorb inorganic ions. By continuously recirculating mineral water in closed piping, hydroponic systems consume up to ninety percent less water than traditional open-field farming.
In competitive exams, questions frequently test commercial techniques and operating parameters. Distinguish between the Nutrient Film Technique, which circulates a continuous thin stream of water over roots, and Aeroponics, which suspends roots in air to be misted with nutrient mist. A favorite prelims trap tests water chemistry: optimal nutrient absorption requires maintaining solution pH between 5.5 and 6.5. Remember that pumps must supply dissolved oxygen to avoid root rot caused by the fungal pathogen Pythium.
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