[Answered] Explain the benefits of micro-irrigation over the conventional irrigation systems. Also mention various challenges in the adoption of this technology.

Micro-irrigation is the slow application of water as discrete or continuous drips, tiny streams or miniature spray on the soil by surface drip and micro-sprinkler systems. As the agriculture sector consumes 80% of the freshwater in India, micro-irrigation is often promoted by central and state governments as a way to tackle the growing water crisis. This is because drip and sprinkler irrigation delivers water to farms in far lesser quantities than conventional gravity flow irrigation.

Benefits of micro irrigation systems:

1. Water saving: Micro-irrigation (MI) is proved to be an efficient method in saving water and increasing water use efficiency as compared to the conventional surface method of irrigation, where water use efficiency is only about 35-40%.
2. Increased irrigation efficiency: The on-farm irrigation efficiency of properly designed and managed drip irrigation systems is estimated to be about 90%. Farmers using a pumping system to irrigate their fields should ensure that the pump and pipe size are fitting with their needs, thus avoiding water and energy overuse and consequent leakages.
3. Higher yields: The yields are higher than traditional flood irrigation. Productivity gain due to use of micro-irrigation is estimated to be in the range of 20 to 90% for different crops. Yields of crops increase up to 45% in wheat, 20% in gram and 40% in soybean.
4. Less water loss: There is also less loss of water due to reduction in loss of water in conveyance and also reduction in loss of water through evaporation, run off, and by deep percolation.
5. Energy efficient: The reduction in water consumption in micro-irrigation also reduces the energy use (electricity) that is required to lift water from irrigation wells.
6. Lower consumption of fertilizers: An efficient drip irrigation system reduces consumption of fertiliser through fertigation.
7. Weed and disease reduction: It helps in inhibiting growth of weeds as it keeps limited wet areas. Under this condition the incidence of disease is also reduced.
8. Cost savings: There are substantial reductions in irrigation costs and savings on electricity and fertilisers.
9. Precision farming: Emerging computerised GPS-based precision irrigation technologies for self-propelled sprinklers and micro-irrigation systems will enable growers to apply water and agrochemicals more precisely and site specifically to match soil and plant status and needs as provided by wireless sensor networks.

Challenges in the adoption of this technology:

1. Electricity: Uninterrupted availability of electric power is required. The electricity unavailability in India affects the timing and supply of water to crops because the crop water requirement in farms neither coincides nor follows India’s timing of power availability or unscheduled power outages.
2. Expensive: The second impediment to micro-irrigation in India is the expense of the system itself. The adoption of this technology has high initial costs.
3. Declining landholdings and farm income: The data on India’s operational landholdings shows that the average size of landholdings have halved since the 1960s. The meagre farm income from declining landholdings challenges the sustainability of expensive micro-irrigation on Indian farms.
4. Maintenance: Micro-irrigation systems normally have greater maintenance requirements. Soil particles, algae, or mineral precipitates can clog the emission devices.
5. Water availability: Though the average water availability in India remains more or less fixed according to the natural hydraulic cycle, per capita availability is reducing progressively owing to the increasing population.

Government of India has also accorded high priority to water conservation and its management. Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) has been formulated with the vision of extending the coverage of irrigation ‘Har Khet Ko Pani’ and improving water use efficiency ‘More crop per drop’ in focused manner using sprinkler & drip method of irrigation. This irrigation method has several advantages over furrow systems, including reduced water use.