Synergistic Impact of Surface and Subsurface Drip Fertigation and Irrigation Scheduling on the Water Use and Productivity of a Basmati Rice–Wheat Cropping System

ABSTRACT Increasing water scarcity and nutrient demand requires efficient irrigation and nutrient management for sustaining the productivity of the basmati rice–wheat cropping system. This study assessed the impacts of two irrigation methods (surface DI and subsurface drip irrigation SDI), four irrigation schedules (I 15% , I 25% , I 35% and I 45% , i.e., 15%, 25%, 35% and 45% depletion of available water) and two nitrogen doses (100% and 75% of the recommended dose), in comparison with the control (flood irrigation with a 100% recommended dose of nitrogen). Compared with the control, the SDI N 100 I 15% , SDI N 100 I 25% , DI N 100 I 15% and DI N 100 I 25% achieved statistically comparable grain yield and yield attributes, with higher water productivity by 10%, 12%, 6% and 9% (pooled from 2021 to 2022 and 2022 to 2023) and irrigation water savings of 185, 255, 145 and 220 mm, respectively, in wheat and basmati rice from 2021 to 2022 and 225, 300, 175 and 265 mm, respectively, in wheat and basmati rice from 2022 to 2023. Furthermore, the highest economic water productivity was recorded in the SDI N 100 I 15% treatment (17.03 INR m −3 pooled) over the control (16.61 INR m −3 pooled) in the basmati rice–heat system. These findings highlight the potential of precision irrigation strategies in enhancing water productivity without compromising yield in the basmati rice–wheat system.