Hydroponics: Definition, History, Types, and Scope in Indian Agriculture
A method of growing plants using mineral fertilizer solutions without soil is called Hydroponics (Greek words “hydro” for water and “ponos” for labour). Growing plants hydroponically necessitates controlling environmental variables such as light intensity and duration, temperature, humidity, pH of the solution/medium, and mineral nutrients. This is why it is also known as “Controlled Environment Agriculture” (CEA). Hydroponics refers to the practice of growing plants without soil.
Thousands of years ago, the study of agricultural nutrition was initiated. Sir Francis Bacon’s 1627 publication of Sylva Sylvarum, a famous treatise on cultivating terrestrial plants without soil, is credited with popularising the technique. Water culture gained popularity as a research technique after Bacon’s work. In his work on tests with spearmint in water culture, John Woodward (1699) noted that “plants thrived better in less pure water sources than plants in distilled water.” Julius von Sachs and Wilhelm Knop, two German botanists, pioneered soilless cultivation methods between 1859 and 1865. Hydroponics was finally coined by Professor William Frederick Gericke in 1937, who also produced the book Complete Guide to Soilless Gardening. The Water Culture Method for Growing Plants without Soil, penned by Dennis R. Hoagland and Daniel I. Arnon, two additional plant nutritionists at the University of California, became a classic in 1938. Hoagland solutions and modified Hoagland solutions, which are still in use today, are just two of the mineral nutrient compositions they created. This method was employed to determine the essentiality standards for several nutrient components.
Hydroponics is essentially divided into two categories: Solution culture and Medium culture.
Solution culture, the roots are supported only by the nutrient solution. there are three main ways to cultivate plants using solution culture:
(a) Static solution culture: In this method, plants are cultivated in tanks, tubs, or buckets made of plastic that contain nutritional solutions. The solution could or might not need to be aerated, but typically it does.
(b) Continuous flow solution culture, such as the nutrient film technique, in which the nutritional solution continuously flows through the roots.
(c) Aeroponics – No substrate is needed, and the roots are suspended in the air in a sealed chamber while being occasionally misted or aerosolized with the nutritional solution in the form of tiny drops. Many laboratory studies of plant physiology involve aeroponics. For their “Controlled Ecological Life Support System,” the National Aeronautics and Space Administration (NASA) has conducted a significant amount of hydroponic research (CELSS). Since a mist is simpler to control under zero gravity than a liquid, special attention has been paid to this technique.
Medium culture, which gets its name from the medium employed, contains a solid medium for the roots.
There are variations for each medium in medium culture, including top irrigation, passive sub-irrigation, flood and drain sub-irrigation, and deep-water culture. Expanded clay, rock wool, coir, perlite, vermiculite, sand, gravel/quartz, and brick shards are some examples of media that can be used to grow plants. The majority of the plant nutrients utilized in hydroponics are inorganic and ionic forms that are dissolved in water. Various chemical mixtures are used to supply each of the 17 components required for plant growth. Fe is kept in soluble form by chelating agents like EDTA. Depending on the crop, the pH of the nutrition solution ranges from 5.6 to 6.0. The content of the nutrient solution changes after the plants have been grown in it because some nutrients are used up more quickly than others, water is absorbed from the solution, and the pH is changed by the excretion of either acidity or alkalinity. The ideal salt content should be chosen with extreme caution to prevent toxicity, early nutrient depletion, or pH alterations, which may all contribute to unintended consequences on plant growth and development.
Scope in Indian Agriculture
Before 1946, hydroponics was not a common practice in India. Kalimpong, Darjeeling’s Experimental Farm was established by the Bengali government. The Bengal System of Hydroponics was created in 1946–1947 as an attempt to satisfy Indian requirements after a detailed analysis of key issues. A few farmers in Gujarat’s southern districts only recently (2008) adopted this technology to grow several exotic hybrid tea rose kinds. Furthermore, the hydroponic system was set out on 12 acres of land in the Navsari district’s Kuch village. Using this technology, exotic crops like strawberries, green garlic, and tomatoes are also grown. “Landmark Agrotech” is the second-largest hydroponics project in Gujarat. To boost agricultural output and use land sustainably, hydroponics can be applied to wastelands in India that have good water availability and poor soil quality.
The following information is gained by hydroponics or soilless culture:
1. The essentiality of mineral elements
2. Deficiency symptoms brought on by the absence of specific nutrients.
3. Potential interactions between various elements found in plants.
4. Toxic effects of excess nutrients on plants
This technique involves adding the nutrient solution to sand, which is utilized as a rooting media.
The following are some drawbacks to this approach
1. Sand is naturally very alkaline, it must be neutralized with acid before use.
2. The sand becomes very warm in the summer and very cold in the winter, which could harm the root system.
3. Sand has a low water holding capacity, it needs to be watered frequently.
Frequently Asked Questions
Question: What is hydroponics?
Ans: A method of growing plants using mineral fertilizer solutions without soil is called Hydroponics (Greek words “hydro” for water and “ponos” for labour). Hydroponics refers to the practice of growing plants without soil.
Question: Is hydroponics better than soil?
Question: Do plants grow quicker in hydroponics?
Ans: Yes, they grow more quickly than soil
Question: How long do hydroponic plants last?
Ans: Most hydroponic plants are capable of surviving without water for about three weeks.
Question: What is the easiest plant to grow hydroponically?
Ans: lettuce, spinach, basil, parsley, oregano, cilantro, mint; tomatoes, strawberries, and hot peppers.