A 2-year field experiment was conducted with the objectives to evaluate the physiological and yield response of quinoa cv Titicaca to various deficit irrigation strategies applied with surface drip (SD) and subsurface drip systems (SSD) under the Mediterranean climatic conditions in 2016 and 2017. The treatments consisted of regulated deficit irrigation (RDI), partial root-zone drying (PRD50), conventional deficit irrigations (DI50, DI75) and full irrigation (FI) under SD and SSD. A rainfed treatment was also included. The experimental design was split plots with four replications. DI75 and DI50 received 75 and 50% of FI, respectively. PRD50 plots received 50% of FI, but from alternative laterals in each application. RDI received 50% of FI during vegetative stage until flowering, then received 100% of water requirement. The results indicated that RDI resulted in water saving of 23 and 21% for surface drip (SD) and SSD systems, respectively, and RDI produced statistically similar yield to FI treatment in both experimental years. DI75 treatment resulted in water savings of 16% for both drip methods in the first year and 10 and 25% for SD and SSD systems, respectively, in the second year. Thus, RDI and DI75 treatments appear to be good alternative to FI for sustainable quinoa production in the Mediterranean environmental conditions. Greater leaf water potential (LWP) and smaller crop water stress index (CWSI) values were measured in FI plots under both drip systems than deficit irrigation treatment plots. Significant second-order polynomial relations were determined between CWSI and LWP for the drip systems. Leaf area index (LAI), LWP decreased and CWSI increased as the drought increased. CWSI correlated significantly (P < 0.01) and negatively with grain yield, dry matter yield, LAI, and mean soil water content indicating that grain yield of quinoa declined with increasing CWSI values. All these relations are best described by significant second-order polynomial equations. The results revealed that quinoa should be irrigated at LWP values between − 1.35 and − 1.60 MPa, and average CWSI value of approximately 0.35 for high yields.

中文翻译：

---

地表和地下滴灌系统差异灌溉藜麦作物水分胁迫指数和叶片水势评估

进行了为期 2 年的田间试验，目的是评估 2016 年和 2017 年地中海气候条件下藜麦 cv Titicaca 对采用地表滴灌 (SD) 和地下滴灌系统 (SSD) 的各种亏缺灌溉策略的生理和产量响应处理包括调节亏缺灌溉（RDI）、部分根区干燥（PRD50）、常规亏缺灌溉（DI50、DI75）和SD和SSD下的全灌（FI）。还包括雨养处理。实验设计是四次重复的裂区。DI75 和 DI50 分别获得 75% 和 50% 的 FI。PRD50 地块获得 50% 的 FI，但来自每个应用程序中的替代侧枝。RDI 在营养阶段直至开花期间接受 50% 的 FI，然后接受 100% 的需水量。结果表明，RDI 分别使表面滴灌 (SD) 和 SSD 系统节水 23% 和 21%，并且在两个实验年中，RDI 产生的产量与 FI 处理在统计上相似。DI75 处理使两种滴灌方法在第一年节水 16%，在第二年 SD 和 SSD 系统分别节水 10% 和 25%。因此，在地中海环境条件下，RDI 和 DI75 处理似乎是 FI 的良好替代品，可用于可持续的藜麦生产。与亏缺灌溉处理地块相比，在两种滴灌系统下的 FI 地块中测量了更​​大的叶水势 (LWP) 和更小的作物水分胁迫指数 (CWSI) 值。滴注系统的 CWSI 和 LWP 之间确定了重要的二阶多项式关系。叶面积指数（LAI），随着干旱加剧，LWP 降低，CWSI 增加。CWSI 与谷物产量、干物质产量、LAI 和平均土壤含水量显着相关 (P < 0.01) 并呈负相关，表明藜麦的谷物产量随着 CWSI 值的增加而下降。所有这些关系最好用重要的二阶多项式方程来描述。结果表明，应在 LWP 值介于 - 1.35 和 - 1.60 MPa 之间以及平均 CWSI 值约为 0.35 的情况下灌溉藜麦，以实现高产量。