ABSTRACT Many nitrogen-efficient (N-efficient) maize cultivars have been bred to meet increased food demand and allay urgent environmental concerns, but the effects of these cultivars on increasing N accumulation and reducing N loss in the maize system have not been reported. A two-year field pot experiment was conducted in Southwest China to evaluate the advantages of an N-efficient maize cultivar on N accumulation and N loss in 2014 and 2015. The results showed that the N-efficient maize cultivar ZH 311 had higher N uptake and accumulation ability than the N-inefficient maize cultivar XY 508, especially in the middle and late growth stages. ZH 311 maintained higher residual soil inorganic N in the appropriate growth stage, promoting soil N supply capability and enhancing N uptake while decreasing residual soil inorganic N at harvest and reducing the risk of N leaching. Higher nitrogen accumulation and residual soil inorganic N contributed to lower apparent N loss and apparent N loss efficiency for the N-efficient cultivar than for the N-inefficient cultivar. Moreover, N loss during the maize growth season mainly occurred before silking, and the N-efficient maize cultivar could effectively reduce N loss before silking because of its earlier N uptake ability. Overall, the selection of N-efficient maize cultivars is not only an important measure to enhance N use efficiency but also an important means to reduce the loss of N and environmental pollution, especially at low and medium N levels.

中文翻译：

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用氮高效玉米品种增加氮积累并减少氮损失

摘要 为了满足日益增长的粮食需求和缓解紧迫的环境问题，已培育出许多高效氮（N-efficient）玉米品种，但这些品种对增加玉米系统中 N 积累和减少 N 损失的影响尚未见报道。2014年和2015年在西南地区进行了为期两年的田间盆栽试验，评价了N高效玉米品种在N积累和N损失方面的优势。结果表明，N高效玉米品种ZH 311具有较高的N吸收量。和积累能力均高于氮低效玉米品种 XY 508，尤其是在生育中后期。ZH 311 在适宜生长阶段保持较高的土壤残留无机氮，提高土壤供氮能力，增强氮吸收，同时减少收获时土壤残留无机氮，降低氮淋失风险。较高的氮积累和残留的土壤无机氮导致氮高效品种的表观氮损失和表观氮损失效率低于氮低效品种。此外，玉米生长季的氮素流失主要发生在吐丝前，而高效氮的玉米品种因其较早的吸氮能力，可有效减少吐丝前的氮素流失。总体而言，选择氮高效玉米品种不仅是提高氮素利用效率的重要措施，也是减少氮素流失和环境污染的重要手段，尤其是在中低氮水平下。较高的氮积累和残留的土壤无机氮导致氮高效品种的表观氮损失和表观氮损失效率低于氮低效品种。此外，玉米生长季的氮素流失主要发生在吐丝前，而高效氮的玉米品种因其较早的吸氮能力，可有效减少吐丝前的氮素流失。总体而言，选择氮高效玉米品种不仅是提高氮素利用效率的重要措施，也是减少氮素流失和环境污染的重要手段，尤其是在中低氮水平下。较高的氮积累和残留的土壤无机氮导致氮高效品种的表观氮损失和表观氮损失效率低于氮低效品种。此外，玉米生长季的氮素流失主要发生在吐丝前，而高效氮的玉米品种因其较早的吸氮能力，可有效减少吐丝前的氮素流失。总体而言，选择氮高效玉米品种不仅是提高氮素利用效率的重要措施，也是减少氮素流失和环境污染的重要手段，尤其是在中低氮水平下。高氮玉米品种由于早吸收氮的能力强，能有效减少吐丝前氮的流失。总体而言，选择氮高效玉米品种不仅是提高氮素利用效率的重要措施，也是减少氮素流失和环境污染的重要手段，尤其是在中低氮水平下。高氮玉米品种由于早吸收氮的能力强，能有效减少吐丝前氮的流失。总体而言，选择氮高效玉米品种不仅是提高氮素利用效率的重要措施，也是减少氮素流失和环境污染的重要手段，尤其是在中低氮水平下。