ABSTRACT It is important to reveal the physiological mechanism of water saving and yield increasing of mulched drip irrigation. Three treatments were applied at aspring maize field in Northeast China: mulched drip irrigation (MD), non-mulched drip irrigation (ND) and rain-fed practice (CK). Result showed that, MD treatment increased 5-year (2014–2018) average grain yield (GY) by 18.6% compared with the CK. The GY showed significant linear positive correlations with photosynthetic capacity (A max ) and maximum carboxylation rate (V cmax ). The 2-year (2017–2018)mean A max and V cmax of MD were significantly increased by 21.1%and 10.7%, respectively, compared with CK, and the increase was partially contributed by the descending of bundle-sheath cells to CO2 (L). The L of MD was decreased by 6.5–12.4% (P< 0.05) during the jointing and tasseling–milk stages. The relationships between A max and leaf nitrogen content (N mass ), and between V cmax and N mass , were affected by mulching treatment, which indicates that the higher leaf Nuse efficiency of the MD treatment. This study provides atheoretical basis for implementation ofmulched drip-irrigation technology,especially in Northeast China.

中文翻译：

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滴灌地膜覆盖通过改善光合特性提高玉米（Zea mays L.）产量和水分利用效率

摘要 揭示地膜滴灌节水增产的生理机制具有重要意义。东北地区春玉米田采用覆膜滴灌（MD）、无覆膜滴灌（ND）和雨育（CK）三种处理方式。结果表明，与CK相比，MD处理使5年（2014-2018）平均谷物产量（GY）提高了18.6％。GY 与光合能力（A max ）和最大羧化速率（V cmax ）呈显着的线性正相关。与CK相比，MD的2年（2017-2018）平均A max 和V cmax 分别显着增加了21.1％和10.7％，并且增加的部分原因是束鞘细胞下降到CO2（ L)。MD 的 L 降低了 6.5-12.4%（P < 0. 05) 在拔节和去雄乳阶段。A max 与叶片氮含量（N mass ）、V cmax 与N mass 之间的关系受覆盖处理的影响，表明MD 处理的叶片Nuse 效率较高。该研究为地膜滴灌技术的实施提供了理论依据，尤其是在东北地区。