Drip irrigation for sustaining high sugarcane (Saccharum officinarum) yield in marginally to moderately waterlogged saline vertisols of Karnataka, India

In the Tungabhadra project command, subsurface drainage is used to reclaim waterlogged saline areas, but its adoption is lower due to its high cost and highly skilled in nature. Irrigation water management could sustain high cane yields in mildly affected areas. A field experiment was conducted on waterlogged saline vertisols with sugarcane crops using surface drip, subsurface drip and furrow irrigation with water application amounts of 0.8, 1.0 and 1.2 of evapotranspiration (ET). The subsurface drip at 1.2 ET resulted in more leaching of salts and a higher moisture content. Also it had the highest cane yield (131.0 t ha⁻¹), water productivity (WP) (8.30 kg m⁻³) and sugar WP (1.72 kg m⁻³) among the different methods. Among the irrigation levels, the 1.2 ET level had the highest cane yield (124.7 t ha⁻¹), lowest WP (6.89 kg m⁻³) and highest sugar WP (1.43 kg m⁻³). The highest benefit–cost ratio was recorded for the subsurface drip treatment. Depth to water table was greater for the subsurface drip treatment compared to the furrow treatment. Therefore, subsurface drip irrigation at 1.2 ET for sugarcane can act as a viable preventive measure for sustaining high cane yield in mildly waterlogged saline vertisols in the command.