With 70-75 per cent of the surface water being utilised for irrigation, there is an urgent need to adopt efficient irrigation techniques to bring down the use of water and increase productivity. At present, a number of irrigation techniques are being used in the country such as free flooding, wells and tube wells, canals and tanks, check basins, centre pivots, and furrow and strip irrigation. However, most of these techniques are inefficient in terms of the amount of water that gets wasted. As a result, the government has been increasingly focusing on encouraging farmers to adopt water-efficient techniques such as micro irrigation.
Construction in the irrigation sector
State governments are actively undertaking a number of irrigation projects to meet the water requirements of the agricultural sector. Some of the key recently completed irrigation projects are the Rs 35 billion Kondapochamma Sagar project under the Kaleshwaram lift irrigation system project in Telangana, the Rs 10.82 billion Muvattupuzha valley irrigation project in Kerala and the Rs 4.75 billion Integrated Anandpur Barrage Project in Odisha, amongst others.
The states of Gujarat, Andhra Pradesh, Rajasthan, Maharashtra, Madhya Pradesh and Telangana have immense upcoming construction opportunity in the irrigation sector. Some of the key upcoming projects in the sector in terms of investment are the Kalpasar dam project (Rs 1 trillion), the Subarnarekha-Mahanadi link (Rs 704.03 billion), the Babu Jagjivan Ram Uttarandhra Sujala Sravanthi Project (Rs 376.52 billion), the Eastern Rajasthan Canal Project (Rs 372.47 billion) and the Ken Betwa River Inter-Linking Project (Rs 349.25 billion).
Further, with respect to the type of irrigation projects, major irrigation projects with a command area of over 10,000 hectares offer substantial construction opportunities.
Typically, construction accounts for a significant share of 50-60 per cent of the total cost of an irrigation project. However, the actual cost of the project depends on a plethora of factors such as the type of irrigation project (minor, medium or major), technique or technology deployed, source of water supply, scope of work and location.
Current techniques and technologies
Wells and tube wells are widely used for lifting of water with a pump set. This is a simple, cost-effective and reliable method of irrigation. However, it cannot be used in areas with salty groundwater and can also lead to groundwater depletion. Canals are most effective for irrigation in areas with deep fertile soils, a perennial water source and an extensive command area. Another commonly used irrigation technique is free flooding, under which the land is divided into plots and the field is watered from the watercourse. The irrigation operation begins at the higher level and proceeds towards the lower levels. Further, the check basin method involves dividing the whole field into basins which are connected through a small drain-type flow way laid along the slope. In furrow and strip irrigation, strips/furrows are created and separated by low embankments and water is diverted from the field channel into the strips.
While all these techniques are effective in irrigating large fields at a low expense, they have resulted in the contamination and depletion of groundwater, calling for a need to adopt more efficient techniques.
An alternative technique
As an alternative to surface irrigation techniques, micro irrigation is now being adopted across the country for increasing water and fertiliser use efficiency, enhancing productivity and improving the quality of crops. Micro irrigation can be of two types – drip irrigation and sprinkler irrigation. Drip irrigation involves dripping water on to the soil at very low rates from a system of small diameter plastic pipes fitted with outlets called emitters or drippers. It is a precise irrigation technique that ensures the maximum use of the available water and saves up to 70 per cent of the resource. Further, it has low operational costs, as there are 30-60 per cent savings in fertiliser use. On the other hand, sprinkler irrigation involves the distribution of water through a system of pipes usually by pumping. Water is then sprayed into the air through sprinklers so that it breaks up into small drops before falling to the ground. It reduces the conveyance loss and saves water use by 30-35 per cent. It is suitable for irrigation where the plant population per unit area is very high. However, there is high initial investment involved in sprinkler irrigation.
Technological advancements
The irrigation sector has witnessed a surge in the adoption of innovative irrigation techniques and technologies as a result of the alarming depletion of water resources. Several agricultural technology start-ups have devised hi-tech micro-irrigation systems such as automated drip and sprinkler irrigation systems supported by soil moisture sensors and a microcontroller. The sensors measure the water availability at different depths in the soil and transmit the information to computers and mobile devices. Rain guns are used to spread water to simulate rain, particularly for sugarcane and maize crops. A major technological innovation in the segment has been the canal network flow monitoring system which monitors canal systems and on-farm parameters using sensors, remote terminal units and information and communications technology. The system facilitates receiving updates on daily water availability, flow and release information, and on-farm information at designated points. Decision-management tools such as computer-based crop-growth simulation models are being adopted as well. They predict potential crop outcomes based on historic climate data, local weather patterns and management practices. This information aids farmers in determining whether additional irrigation is needed to achieve their production goals based on the projected yield. The adoption of information technology and geographic information systems is expected to enable complete online tracking of the micro-irrigation system.
Issues and challenges
The high cost of micro irrigation and the low income of farmers has been the biggest challenge for technology deployment. The expenditure requirement for on-farm micro-irrigation equipment and machinery such as drips, mini sprinklers, pressure guns and centre pivot is high and exceeds the purchasing capacity of farmers. Further, the power requirement for the operation of micro-irrigation systems is high, making it costlier than other irrigation techniques. Small farm sizes too makes the system very complex and difficult to operate by the farmers. Moreover, the sector is unprofitable for private sector participation and is largely dependent on government investments due to the poor paying capacity of farmers.
The way forward
The central government has made concerted efforts towards strengthening irrigation infrastructure via its flagship programmes and initiatives such as the Pradhan Mantri Krishi Sinchayee Yojana, the Command Area Development and Water Management and the Interlinking of Rivers Programme. It has opened the gateway of investment opportunities for the stakeholders involved, including pipe and pump manufacturers, flow meter manufacturers, storage system providers, technology providers and consultants.
With half the country’s cultivable land still being rain fed, there is huge potential for promoting micro irrigation and related technology applications in the upcoming irrigation projects. Providing infrastructure status to the micro-irrigation industry can reduce some of the operating costs for manufacturers on account of incentives and thus reduce the cost of equipment for farmers. Given the large untapped potential in micro-irrigation coverage, there exists ample opportunity for private players to take up integrated micro-irrigation projects on a public-private partnership basis.
Irrigation technologies are being developed to use water optimally by providing moisture rather than concentrated loads of water. Micro irrigation has grown from a forced technology to a demand-driven one. Integration of traditional methods with modern-day technologies is required to align the technology to local requirements. Further, effective training and awareness generation among small and marginal farmers through field demonstrations and enhancing their capacity to adopt the technology is critical for its successful implementation.