Drip irrigation as a strategy for sustainable paddy cultivation in waterlogged saline Vertisol of TBP command area, Karnataka

A field experiment on drip irrigation for sustaining puddle transplanted rice yields in waterlogged saline Vertisol was conducted at Agricultural Research Station, Gangavathi, Karnataka during Kharif 2022, Rabi/Summer-2022-23 and Kharif 2023. The experiment consisted of two paddy varieties (GVT-05-01 and GNV-1801) as main-plot treatments and surface drip with water application amounts of 1.2, 1.4, 1.6 and 1.8 of evapotranspiration, (ET) as sub-plot treatments in a split-plot design. Varieties did not had significant effect on soil moisture content and soil salinity across the crop growth stages however, the soil moisture content was significantly higher at 1.8 ET and was on par with 1.6 and 1.4 ET level both at surface and subsurface soil across the crop growth stages during all the three cropping seasons. Soil salinity was generally significantly highest at 1.2 ET compared at other ET in both surface and subsurface soil during all the three cropping seasons. The yield and water use efficiencies (WUE) were significantly higher in GNV-1801 as compared to GVT-05-01 and among different irrigation levels 1.6 ET had significantly higher yield (6746, 5606 and 6592 kg ha^-1) and WUE (82.52, 77.9 and 80.56 Kg (ha-cm)^-1) during Kharif 2022, Rabi/Summer-2022-23 and Kharif 2023, respectively compared to rest of the treatments but was on par with 1.4 ET during all the three cropping seasons. Similar to growth and yield, net returns and BC ratios were significantly higher under variety GNV-1801 and ET 1.6 compared to GVT-05-01 and rest of the ET treatments but was on par with 1.4 ET respectively during all the three cropping seasons. In conclusion, farmers at the tail end of canal command who often faces acute shortage of irrigation water can opt for drip irrigation to enhance the water usage thus can overcome the ill effects of secondary salinization and waterlogging.