Abstract Maize (Zea mays L.) is highly susceptible to zinc (Zn) deficiency. Different application strategies (AS) can be utilized to improve grain yield (GY) and quality (Zn biofortification) by combining Zn fertilizer rate, source, timing, and placement techniques. This study aimed to evaluate whether different Zn-AS (soil, seed, and foliar) affect maize GY and grain Zn concentration in Mollisols with contrasting soil Zn availability and pH. Five site-years field experiments were carried out. Treatments (Zn-AS) were compared to a control, and included: seed-Zn, 0.3 kg Zn ha−1; foliar-Zn, 0.7 kg Zn ha−1 at V6 stage; and soil-Zn, 2.1 kg Zn ha−1 surface banded. Zinc fertilization increased GY (response ranged from 892 to 2519 kg ha−1) in four of five sites (p < 0.05). The evidence indicates that in scenarios of very low soil Zn availability (<0.9 mg kg−1 Zn-DTPA) greater Zn rates are required, and therefore soil-Zn and foliar-Zn are the more suitable AS. Grain Zn concentration ranged from 19.5 to 43.1 mg kg−1 and was not affected by Zn-AS. At all sites, even those showing GY response to Zn fertilization, grain Zn concentration in the control treatment was above the sufficiency threshold for maize GY (18 mg kg−1), indicating that this threshold needs to be updated for the current maize hybrids. Grain Zn concentration was predicted by the model: grain Zn concentration = 39.56 − 0.002 × GY + 9.62 × Zn-DTPA (R2 = 0.38).

中文翻译：

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施锌策略对玉米籽粒产量和软土中锌浓度的影响

摘要 玉米 (Zea mays L.) 对锌 (Zn) 缺乏非常敏感。通过结合施锌量、来源、时机和放置技术，可以利用不同的施用策略 (AS) 来提高粮食产量 (GY) 和质量（锌生物强化）。本研究旨在评估不同的 Zn-AS（土壤、种子和叶面）是否会影响 Mollisol 中的玉米 GY 和谷物 Zn 浓度，并具有对比的土壤锌可用性和 pH 值。进行了五年现场试验。将处理（Zn-AS）与对照进行比较，包括：种子-Zn，0.3 kg Zn ha-1；叶面锌，V6 阶段 0.7 kg Zn ha-1；和土壤-Zn，2.1 kg Zn ha−1 表面带状。在五个地点中的四个地点，锌肥增加了 GY（响应范围为 892 至 2519 kg ha-1）（p < 0.05）。证据表明，在土壤锌含量极低的情况下（< 0.9 mg kg-1 Zn-DTPA）需要更高的锌含量，因此土壤锌和叶面锌是更合适的 AS。谷物 Zn 浓度范围为 19.5 至 43.1 mg kg-1，不受 Zn-AS 的影响。在所有地点，即使是那些对锌施肥显示 GY 响应的地点，对照处理中的谷物 Zn 浓度高于玉米 GY 的充足阈值（18 mg kg-1），这表明需要为当前的玉米杂交品种更新该阈值。颗粒锌浓度由模型预测：颗粒锌浓度 = 39.56 − 0.002 × GY + 9.62 × Zn-DTPA (R2 = 0.38)。对照处理中的谷物 Zn 浓度高于玉米 GY 的充足阈值（18 mg kg-1），这表明当前玉米杂交种需要更新该阈值。颗粒锌浓度由模型预测：颗粒锌浓度 = 39.56 − 0.002 × GY + 9.62 × Zn-DTPA (R2 = 0.38)。对照处理中的谷物 Zn 浓度高于玉米 GY 的充足阈值（18 mg kg-1），这表明当前玉米杂交种需要更新该阈值。颗粒锌浓度由模型预测：颗粒锌浓度 = 39.56 − 0.002 × GY + 9.62 × Zn-DTPA (R2 = 0.38)。