The correct answer is Check dams. Explanation & Key Takeaways: • Check dams are primarily constructed to conserve water by slowing down the flow of small streams or rivers. They help in water harvesting and groundwater recharge but are not classified as a formal method of irrigation. Hence, check dams are not a method of irrigation. • River lift systems are a recognized irrigation method. They involve lifting water from rivers using pumps or other mechanisms to supply water to agricultural fields. This statement is correct. • Canals are an integral part of irrigation systems. They are constructed to divert water from rivers or reservoirs to agricultural lands. This statement is correct. • Wells are one of the oldest and most common irrigation methods. Farmers draw water from underground sources using wells for irrigation purposes. This statement is correct. • Check dams, unlike canals, wells, and river lift systems, do not directly supply water to agricultural fields for irrigation. They are used for water conservation and storage but not for direct irrigation. Related Concepts: • Check Dams: • These are small, low structures built across streams or rivers to reduce water flow and promote groundwater recharge. • They are commonly used for soil conservation and preventing erosion in hilly or semi-arid areas. • Check dams are not designed to directly supply water for irrigation but support water availability in nearby areas. • River Lift Irrigation: • This method involves pumping water from rivers to higher elevation areas for agricultural purposes. • It is particularly useful in regions where gravitational water flow is not possible. • Examples of river lift irrigation projects can be found in India, such as the Godavari Lift Irrigation Scheme in Telangana. • Canals: • Canals are man-made channels designed to carry water from rivers or reservoirs to agricultural lands. • They are a major source of irrigation in India, especially in states like Punjab, Haryana, and Uttar Pradesh. • The Indira Gandhi Canal in Rajasthan is one of the largest canal irrigation projects in the world. • Wells: • Wells are excavations in the ground to access underground water for irrigation and other purposes. • Tube wells and dug wells are common types of wells used for irrigation. • India has a significant dependency on well irrigation, especially in regions like Gujarat, Maharashtra, and Tamil Nadu. Important Notes: • Classification of Irrigation Methods: • Surface Irrigation: Includes canals, tanks, and river lift systems. • Subsurface Irrigation: Relies on underground water sources accessed through wells. • Micro-Irrigation: Includes drip and sprinkler irrigation, promoting water efficiency. • Role of Water Conservation: • Structures like check dams and percolation tanks play a vital role in replenishing groundwater but do not directly irrigate fields. • These measures are essential in drought-prone and water-scarce regions to ensure sustainable water availability. • Government Initiatives: • Programs like the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) promote efficient water management and irrigation practices in India. • PMKSY focuses on ‘Har Khet Ko Pani’ and improving on-farm water use efficiency.