Improving the productivity of limited land and water resources is necessary to meet the increasing demand for food and feed. A 2-year (2016–18) field study was conducted in a humid climate in the north of Iran to examine the effect of different drainage systems on green water-use efficiency (GWUE), economic water productivity (EWP) and yield and growth indices of winter canola. The treatments consisted of surface drainage (Control) and three conventional subsurface drainage systems. Leaf area index (LAI) and total dry weight were measured randomly during different growth stages. The traits were then used to determine crop growth rate and relative growth rate. Subsurface drainage significantly improved yield and growth indices as well as GWUE and EWP compared with Control, with grater effectiveness under wet season. Yield, GWUE and EWP increase in subsurface drainage systems compared to surface drainage ranged from 460–890 and 825–1090 kg ha⁻¹, 0.13–0.25 and 0.22–0.29 kg m⁻³ and 0.04–0.08 and 0.07–0.09 US $ m⁻³ in 2016–2017 and 2017–2018 growing seasons, respectively. Mean LAI in the subsurface drained area was 23–24% and 5–10% more than that in Control in the first and second growing seasons, respectively. The results indicated that an appropriate subsurface drainage system as well as a management strategy is necessary to prevent potential adverse effects of waterlogging in wet seasons and to increase land and water productivity in the study area.

为了满足对粮食和饲料日益增长的需求，必须提高有限土地和水资源的生产力。在伊朗北部潮湿的气候下进行了为期2年（2016-18年）的实地研究，研究了不同排水系统对绿色用水效率（GWUE），经济水生产率（EWP）以及产量和增长的影响冬季油菜指数。处理包括地面排水（控制）和三个常规地下排水系统。在不同的生长阶段随机测量叶面积指数（LAI）和总干重。然后将这些性状用于确定作物生长速率和相对生长速率。与对照相比，地下排水显着提高了产量和生长指数以及GWUE和EWP，并且在雨季具有更高的磨碎效果。产量，^-1，0.13-0.25和0.22-0.29公斤米^-3和0.04-0.08和0.07-0.09 US $米^-3，分别在2016至17年和2017年至2018年的生长季节。在第一个和第二个生长季节，地下流域的平均LAI分别比对照高23–24％和5–10％。结果表明，适当的地下排水系统和管理策略对于防止潮湿季节内涝的潜在不利影响以及增加研究区域的土地和水生产力是必要的。