The efficiency of cyclic irrigation (CI) (using river water (RW) and drainage water (DW)) was investigated and compared with normal irrigation (NI) (using only RW). A 24 × 30 m research area was selected and divided into three plots – A (maize), B (soybean) and C (sunflower). Plot A was designed to produce DW for the irrigation of plots B and C. In plot B, a split-plot design was applied with randomised complete blocks with two treatments: irrigation type and rate of urea fertiliser application. The experimental design of plot C was similar to that of plot B except for the rate of fertiliser application. Analysis of variance (Anova) results for soybean revealed that the interaction between irrigation type and urea level had significant effects on growth yield and biological water productivity (WP) (P < 0.01) and fresh leaf weight (P < 0.05). The Anova results for sunflower showed that the interaction between irrigation type and urea level had significant effects on 100-seed weight, seed yield and seed WP (P < 0.05). The highest increase in WP for sunflower was for forage WP (0.768 kg/m³ for NI and 2.603 kg/m³ for CI). The WP of RW for total forage, total seed and total biological yields for CI compared with NI increased by 76.67%, 72.95% and 75.45%, respectively. The lowest increase in WP was for sunflower seed yield (0.276 kg/m³ for NI and 0.821 kg/m³ for CI). Overall, the data showed that, compared with NI, CI led to water savings of 45.59% and increased WP.

中文翻译：

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循环灌溉对产量、产量构成和水生产率的有效性

研究了循环灌溉（CI）（使用河水（RW）和排水（DW））的效率，并与正常灌溉（NI）（仅使用RW）进行比较。选择24×30 m的研究区域并分为三个样地——A（玉米）、B（大豆）和C（向日葵）。地块 A 的设计目的是为地块 B 和 C 的灌溉产生 DW。在地块 B 中，采用裂区设计，采用随机完整区块，并进行两种处理：灌溉类型和尿素肥料施用率。除施肥量不同外，C区的试验设计与B区类似。大豆方差分析（Anova）结果显示，灌溉类型和尿素水平之间的交互作用对生长产量、生物水分生产率（WP）（P  < 0.01）和鲜叶重量（P  < 0.05）有显着影响。向日葵的方差分析结果表明，灌溉类型与尿素水平的交互作用对百粒重、种子产量和种子可湿性有显着影响（P  < 0.05）。向日葵的WP 增幅最大的是饲料WP（NI 为0.768 kg/m ^{3 ，CI 为2.603 kg/m 3}）。 CI 的 RW 总牧草产量、总种子产量和总生物产量与 NI 相比分别提高了 76.67%、72.95% 和 75.45%。 WP 增幅最低的是葵花籽产量（NI 为0.276 kg/m ^{3 ，CI 为 0.821 kg/m 3}）。总体而言，数据显示，与 NI 相比，CI 节水 45.59%，并增加了 WP。