Hydroponics: Growing Plants without Soil - Class 8 Vocational Education

Hydro = water, Ponos = labour or work. Hydroponics means “water work,” referring to growing plants in nutrient-rich water without soil.

Hydroponics is promoted because about 33% of India’s land is degraded. It avoids dependence on soil and helps overcome nutrient loss, deforestation, and over-irrigation issues.

Crop rotation is a traditional soil-based farming technique. Wick, DWC, and NFT are the three hydroponic systems explained in the chapter.

In the Wick method, a cotton wick pulls nutrient water upwards to the plant medium using capillary action. It requires no electricity.

In DWC, plant roots are submerged in water. An aerator supplies oxygen, keeping roots healthy (white). Without oxygen, roots turn brown.

Plants grow best when hydroponic water is slightly acidic to neutral, between pH 6.0 and 7.0.

Weak acids like citric acid and vinegar are safe for adjusting pH. Strong acids (sulfuric, nitric, phosphoric) are unsafe for students.

Since hydroponics does not use soil, compost tea (liquid manure) supplies nutrients and beneficial microbes that normal compost would provide.

Hydroponics supports vertical (multistorey) farming in urban areas, producing more crops in less space with efficient water reuse.

In NFT, roots are placed in a thin flowing film of nutrient-rich water inside PVC pipes. The flowing water supplies both nutrients and oxygen.