Opt for conjunctive use of canal, groundwater: PAU experts

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Ludhiana, July 9

With the state’s agriculture facing its worst water crisis, the Punjab Agricultural University (PAU) has released the findings of a comprehensive study conducted by its Department of Soil Science on ‘Groundwater Quality in the South-Western Region’ during the years 2020-23. The study was carried out by collecting and evaluating 2,664 samples from various districts.

Referring to the research findings, Dr Dhanwinder Singh, head, Department of Soil Science, disclosed that the results were concerning with the high salinity levels in most of the groundwater samples, some exceeding 10,000 micro-Siemens/cm. “Only 30.5 per cent of the samples were found fit for irrigation, while 53.1 per cent were marginal and 16.4 per cent were unfit due to high residual sodium carbonate (RSC) and electrical conductivity (EC),” he added. Further, Dr Singh observed that the application of such water affected soil health, particularly in rice-wheat systems.

In the southwestern zone, which received less rainfall and had high soil and groundwater salinity, farmers should adopt a conjunctive use of canal and groundwater in large areas with available canal water supplies, to mitigate the adverse effects of sodic water irrigation, advised Dr Singh. Elaborating, he said that alternating sodic and canal water irrigation showed sustainable crop yields and helped in maintaining soil health.

Dr Ajmer Singh Dhatt, Director of Research, highlighted the implications of the Central Ground Water Assessment Board’s 2022 report which categorized 114 out of 150 assessed blocks as over-exploited. He observed that the dependency on groundwater has increased significantly over the past 60 years, particularly in the central districts where mismanagement has led to severe depletion. Conversely, the southwestern districts faced challenges with poor-quality groundwater, posing a serious threat to sustainable crop production, he pointed out.

Dr Dhatt added that despite the extensive canal network of about 14,500 km long, canal water usage remained limited, especially in central districts having good quality groundwater. The state government has made concerted efforts to improve canal water supply, even reaching tail-end villages, however, underutilisation persisted in districts like Barnala, Sangrur, Patiala, Ludhiana and Moga, he added. “Farmers of these districts often prefer groundwater due to its ease of use, but this short-term benefit compromises long-term sustainability. It is imperative to balance immediate needs with ecological benefits for future generations,” urged Dr Dhatt.

Drawing attention to the current scenario of depleting water resources, Dr Satbir Singh Gosal, vice-chancellor, PAU, has emphasised the urgent need for a strategic approach to water management. “Our state has 99 per cent of cultivable area under irrigation – 28 per cent from canal water and 72 per cent from tubewells. The state relies heavily on both surface water and groundwater for irrigation, but the latter’s excessive use has led to alarming depletion rates,” he observed.

In conclusion, Dr Dhanwinder Singh underscored that Punjab’s water crisis demanded an integrated approach, leveraging utilization of both canal and groundwater resources wisely. “Our agricultural future depends on sustainable practices. By optimising canal water usage and managing groundwater judiciously, we can ensure higher crop yields and preserve soil health,” Dr Singh affirmed.