Evaluating Water Requirements and Yield Response of Wheat Varieties under Canal and Marginal Groundwater Irrigation

Water scarcity and irrigation water quality pose critical challenges in wheat cultivation. This study evaluates the water requirements, yield, and water productivity of three wheat varieties: NIA Amber, NIA Sarang, and NIA Zarkhaiz, under surface water (EC 0.5 – 1 dS / m ) and marginal groundwater (EC 2 – 2.5 dS / m ) irrigation, using minilysimeters at the Drainage and Reclamation Institute of Pakistan (DRIP) during the 2023–2024 wheat season. Under surface water, NIA Amber had the highest crop water requirement (CWR) at 450 mm, followed by NIA Zarkhaiz (440 mm) and NIA Sarang (424 mm). Marginal groundwater irrigation slightly reduced CWR, ranging from 426 to 432 mm. The crop coefficient (Kc) ranged from 1.07 to 1.81 for surface water and from 1.03 to 1.77 for groundwater. NIA Amber produced the highest yield under surface water ( 7,116 kg / ha ), whereas NIA Zarkhaiz performed best under marginal groundwater ( 5,836 kg / ha ). Crop water productivity (CWP) was highest for NIA Amber under surface water ( 1.58 kg / m 3 ) and for NIA Zarkhaiz under marginal groundwater ( 1.35 kg / m 3 ). The study suggests that NIA Amber is optimal for areas with high-quality surface water, whereas NIA Zarkhaiz is better suited for regions with marginal groundwater. These findings inform wheat variety selection based on local water quality, enhancing water-use efficiency and productivity.