It expects students to explain various decentralised irrigation techniques. It also expects students to write about the benefits of these irrigation techniques as per agro-climatic conditions of India.
Introduction:
Irrigation is the prime most component in the agriculture sector in India. As more than three quarters of the annual rainfall occurs during the four months of the summer monsoon season, decentralised irrigation techniques play the pivotal role to ensure water supply for agriculture & household needs round the year.
Body:
Decentralised irrigation refers to the small-scale, storage and distribution of water for agricultural and other needs in rural as well as urban areas. Various decentralised irrigation techniques are as follows:
Farm ponds: Farm ponds are small tank or reservoir like constructions, are constructed for the purpose of storing the surface runoff, generated from the catchment area. The farm ponds are the water harvesting structures, solve several purposes of farm needs such as supply of water for irrigation, cattle feed, fish production etc.
Rain water harvesting: Rainwater harvesting has agricultural uses. It can be used to water crop plants in agricultural fields, improve ground water table. For instance, Work done by Paani foundation in selective rural areas has led to improvement in ground water table.
Surface irrigation: Water is distributed over and across land by gravity, no mechanical pump involved.
Localized irrigation: Water is distributed under low pressure, through a piped network and applied to each plant.
Drip irrigation: A type of localized irrigation in which drops of water are delivered at or near the root of plants. In this type of irrigation, evaporation and runoff are minimized.
Sprinkler irrigation: Water is distributed by overhead high-pressure sprinklers or guns from a central location in the field or from sprinklers on moving platforms.
Benefit of decentralised irrigation as per India’s agro-climatic conditions:
India accounts for only about 4 % of global water resources, where agriculture consumes more than 80 % of the total usable water available in the country.
Decentralised irrigation offer the possibility to provide adequate water where centralised supply systems are not feasible due to technical, economical or institutional reasons. Ex: In rural communities or informal settlements.
Small water bodies (mainly tanks) are less capital-intensive, user-friendly with fewer environmental problems and augment groundwater resources through sub-surface recharge. Ex: Existence of decentralised water storage systems in (Hebbal) Bengaluru, etc.
Decentralised supply offers the possibility to provide clean, reliable drinking water to rural or informal settlements where centralised systems are not economically or technically possible.
Wide range of simple, relatively inexpensive and cost effective options are available so people can choose the technologies most appropriate for them. Ex: Drip irrigation, Sprinkler technique, etc.,
Traditional irrigation techniques such as tankas, khadins, vav, ahar pynes are significant in areas such as arid and semi-arid regions. Ex: Bikaner, Jaisalmer, South Bihar.
They are independent from an institutional set-up or centralised systems. Hence do not carry the major drawbacks of centralised irrigation system.
Government initiatives to promote decentralised irrigation:
Mission Kakatiya is a flagship program under Telangana government aimed at restoring minor irrigation sources of water like ponds and tanks.
Jalyukt Shivar yojan in Maharshtra has played a prominent role in providing farm ponds to every farmer in her/his agriculture field.
In Gujarat ‘Bhungroo’ a water management system that injects and stores excess rainfall water underground. This water is then used for irrigation during summers .
Conclusion:
World Banks report on “India’s Water Economy: Bracing for a Turbulent Future” (2006), stated that dams in India have the capacity to store only about 30 days of rainfall, compared with 900 days in major river basins in arid areas of developed countries. Hence, it becomes important to focus more on decentralised irrigation as it will help the agriculture sector to be self reliant (Aatmnirbhar) in irrigation.
