<P> Irrigation in India includes a network of major and minor canals from Indian rivers, groundwater well based systems, tanks, and other rainwater harvesting projects for agricultural activities . Of these groundwater system is the largest . In 2013 - 14, only about 47.7% of total agricultural land in India was reliably irrigated . The largest canal in India is Indira Gandhi Canal, which is about 650 km long . About 2 / 3rd cultivated land in India is dependent on monsoons . Irrigation in India helps improve food security, reduce dependence on monsoons, improve agricultural productivity and create rural job opportunities . Dams used for irrigation projects help produce electricity and transport facilities, as well as provide drinking water supplies to a growing population, control floods and prevent droughts . </P> <P> The earliest mentions of irrigation are found in Rigveda chapters 1.55, 1.85, 1.105, 7.9, 8.69 and 10.101 . The Veda mentions only well - style irrigation, where kupa and avata wells once dug are stated to be always full of water, from which varatra (rope strap) and cakra (wheel) pull kosa (pails) of water . This water was, state the Vedas, led into surmi susira (broad channels) and from there into khanitrima (diverting channels) into fields . </P> <P> Later, the 4th - century BCE Indian scholar Pāṇini, mentions tapping several rivers for irrigation . The mentioned rivers include Sindhu, Suvastu, Varnu, Sarayu, Vipas and Chandrabhaga . Buddhist texts from the 3rd century BCE also mention irrigation of crops . Texts from the Maurya Empire era (3rd century BCE) mention that the state raised revenue from charging farmers for irrigation services from rivers . </P> <P> Patanjali, in Yogasutra of about the 4th century CE, explains a technique of yoga by comparing it to "the way a farmer diverts a stream from an irrigation canal for irrigation". In Tamil Nadu, the Grand Anicut (canal) across the Kaveri river was implemented in the 3rd century CE, and the basic design is still used today . </P>

In which state of india is maximum area irrigated by tube well