Abstract The objective of this study was to determine whether grain yield and nitrogen (N) use efficiency (NUE) in winter wheat (Triticum aestivum L.) could be improved by alternate furrow irrigation (AFI). During the 2009–2010 and 2010–2011 crop seasons, the effects of AFI on grain yield, NUE (and its components), the recovery of 15N-labeled fertilizer, N uptake and distribution, and soil nitrate-N were evaluated under field conditions. The irrigation regimes were: W0, non-irrigated; W2, every furrow irrigated at jointing and anthesis; W3, every furrow irrigated before wintering and at jointing and grain filling; and AFI, each of two neighboring furrows irrigated either before wintering or at grain filling, and every furrow irrigated at jointing. Our results show that grain yield, above-ground nitrogen uptake (AGN; including N from fertilizers and soil), and NUE were lowest in the W0 treatment and tended to increase with increasing irrigation frequency. Grain yield, AGN (including N from fertilizers and soil), NUE, nitrogen uptake efficiency (UPE), 15N-recovery efficiency, and N accumulation in grains were significantly higher in the AFI treatment than in the W2 treatment. AGN increased due to a higher amount of N derived from both fertilizers and soil. More N was derived from soil than from fertilizers; thus, the proportion of N derived from fertilizers decreased. No significant differences in grain yield and NUE were observed between the AFI and W3 treatments. AGN decreased when soil N luxury uptake and N accumulation in stems and leaves decreased. Greater N utilization efficiency and a higher N harvest index were observed in the AFI treatment compared with the W3 treatment. In addition, AFI increased nitrate-N contents in the upper soil layer (0–60 cm) and reduced nitrate-N movement to deeper soil compared to the W2 and W3 treatments. Therefore, AFI may be an appropriate irrigation method for improving NUE and decreasing water consumption in winter wheat without reducing yield.

中文翻译：

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交替沟灌提高冬小麦的产量和氮素利用效率

摘要 本研究的目的是确定交替沟灌（AFI）是否可以提高冬小麦（Triticum aestivum L.）的谷物产量和氮（N）利用效率（NUE）。在 2009-2010 和 2010-2011 作物季节期间，在田间条件下评估了 AFI 对粮食产量、NUE（及其成分）、15N 标记肥料的回收、N 吸收和分配以及土壤硝酸盐-N 的影响. 灌溉制度是：W0，非灌溉；W2，拔节和开花时每沟浇水；W3，越冬前、拔节和灌浆时每沟浇一次水；和 AFI，两个相邻的犁沟在越冬前或灌浆时灌溉，每条犁沟在拔节时灌溉。我们的结果表明谷物产量、地上氮吸收量 (AGN; 包括来自肥料和土壤的 N），NUE 在 W0 处理中最低，并且随着灌溉频率的增加而增加。AFI处理的谷物产量、AGN（包括肥料和土壤中的N）、NUE、氮吸收效率（UPE）、15N-回收效率和谷物中的N积累显着高于W2处理。AGN 增加是由于来自肥料和土壤的氮含量增加。来自土壤的氮多于来自肥料的氮；因此，来自肥料的氮的比例下降。在 AFI 和 W3 处理之间没有观察到谷物产量和 NUE 的显着差异。当土壤对氮的奢侈吸收和茎叶中氮的积累减少时，AGN 减少。与 W3 处理相比，在 AFI 处理中观察到更高的氮利用效率和更高的氮收获指数。此外，与 W2 和 W3 处理相比，AFI 增加了上层土层（0-60 cm）中硝酸盐-N 的含量并减少了硝酸盐-N 向深层土壤的迁移。因此，AFI 可能是一种在不降低产量的情况下提高冬小麦 NUE 和减少水分消耗的合适灌溉方法。