Indian Journal of Ecology

Subsurface drip irrigation (SDI) is an emerging micro-irrigation technique, particularly promising for close-spaced crops like wheat. SDI minimizes evaporation losses by delivering water directly to the root zone, potentially enhancing yield with reduced water consumption. This field study, conducted at Punjab Agricultural University’s Regional Research Stations in Abohar and Faridkot, investigated fertigation scheduling and wheat performance under deficit SDI regimes. Treatments included three SDI levels (60, 80, and 100% of crop evapotranspiration, ETc) combined with two fertigation levels (60 and 80% of the recommended nitrogen dose, RDN), alongside a surface flood irrigation control (100% RDN). SDI at 80 and 100% ETc significantly increased grain yield by 9.3 and 12.1%, respectively, compared to the control, with corresponding increases of 10.1 and 12.9% over 60% ETc. Both fertigation levels yielded higher grain yields (5.5-8.3% increase over control), but no significant difference was observed between them. SDI improved nitrogen use efficiency (NUE), peaking at 80% and 100% ETc. Water savings with SDI ranged from 54.5-66.0% in Abohar to 27.9-46.8% in Faridkot, compared to the control. The 60% ETc treatment, with the least water application, achieved the highest apparent water productivity (AWP), followed by 80% and 100% ETc under SDI. Surface flood irrigation resulted in the lowest AWP due to lower yield and higher water use. This study indicates that SDI at 80% ETc, coupled with fertigation at 60% RDN, optimizes wheat yield and AWP.