In arid and semiarid environments, with shortage of water resources, maize production is competing for available water. This study analyzed the effect of different irrigation systems on maize yield, crop evapotranspiration and its components, i.e., canopy transpiration ( T ) and soil evaporation ( E ). A 2-year field experiment was conducted at the ITAP Research facilities located in Albacete (southeast Spain). Four treatments were assessed: surface drip irrigation with a spacing between drip lines of 1.5 m (SDI_1.5) and 0.75 m (SDI_0.75); subsurface drip irrigation (SubDI); solid set sprinkler irrigation (Sprink). In all treatments, irrigation was applied to refill the estimated potential water demand. Crop evapotranspiration ( ET c ) and E / T partitioning were estimated using a Simplified Two-Source Energy Balance (STSEB) approach. Although there was an important difference in the irrigation water applied between treatments, ranging from 743 and 722 for Sprink system to 534 and 495 for SubDI system in 2014 and 2015, respectively, yield was unaffected by the irrigation regime, resulting in an increase in the irrigation water productivity (IWP) by an average of 25% when irrigation was applied by the subsurface system. Maize ET c was affected by the irrigation system, with the SubDI achieving in 2015 a 39% reduction of seasonal ET c in comparison with the Sprink system. Similar reductions were obtained for separated E and T components with soil evaporation accounting in general for 15–20% of the total ET c . It is concluded that subsurface irrigation is a water savings strategy for irrigation of maize reducing the consumptive water use and increasing IWP. The final convenience for the widespread adoption of subsurface irrigation will depend on water availability and prices.

中文翻译：

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半干旱环境下喷灌、地表和地下滴灌下玉米蒸散量和产量性能比较

在干旱和半干旱环境中，由于水资源短缺，玉米生产正在争夺可用水。本研究分析了不同灌溉系统对玉米产量、作物蒸散量及其组成部分的影响，即冠层蒸腾量 (T) 和土壤蒸发量 (E)。在位于阿尔瓦塞特（西班牙东南部）的 ITAP 研究设施中进行了为期 2 年的实地试验。评估了四种处理：地表滴灌，滴水线之间的间距为 1.5 m (SDI_1.5) 和 0.75 m (SDI_0.75)；地下滴灌（SubDI）；固集喷灌（Sprink）。在所有处理中，灌溉用于补充估计的潜在需水量。使用简化的双源能量平衡 (STSEB) 方法估算作物蒸散量 (ET c ) 和 E/T 分配。尽管处理间灌溉水量存在重要差异，从 Sprink 系统的 743 和 722 到 SubDI 系统的 534 和 495，分别在 2014 年和 2015 年，但产量不受灌溉制度的影响，导致当采用地下系统灌溉时，灌溉水生产力 (IWP) 平均提高 25%。玉米 ET c 受到灌溉系统的影响，与 Sprink 系统相比，SubDI 在 2015 年实现了季节性 ET c 减少 39%。分离的 E 和 T 组分获得了类似的减少，土壤蒸发一般占总 ET c 的 15-20%。得出的结论是，地下灌溉是玉米灌溉的节水策略，减少了耗水量，增加了 IWP。