Determining soil Zn thresholds for wheat (Triticum aestivum L.) is still challenging because soil Zn tests have been poorly calibrated. Therefore, this work aimed to determine, under field conditions, the diethylenetriaminepentaacetic acid (DTPA)–Zn critical threshold for wheat grain yield (GY) response to Zn fertilization in noncalcareous Mollisols. We conducted 14 Zn-fertilization field trials in Typic Argiudolls from the Argentinean Pampas. Zinc fertilization increased GY in 6 out of 14 trials. Wheat GY response to Zn fertilization ranged from 300 to 949 kg ha^–1. Our DTPA–Zn threshold is the first one determined by field trials for wheat grown in Mollisols (1.03 mg kg⁻¹, with a 95% confidence interval from 0.87 to 1.23 mg kg⁻¹). This threshold was greater than those previously reported for other soil types. Future studies should compare different Zn-fertilization strategies for wheat on Mollisols by combining different fertilizer rates, sources, timings, and placements.

中文翻译：

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小麦籽粒产量对 Mollisol 中锌施肥响应的 DTPA 可提取锌阈值

确定小麦 ( Triticum aestivum L.) 的土壤锌阈值仍然具有挑战性，因为土壤锌测试校准不当。因此，这项工作旨在确定在田间条件下，二亚乙基三胺五乙酸 (DTPA)-Zn 对小麦籽粒产量 (GY) 响应的非钙质 Mollisol 中施锌的临界阈值。我们在阿根廷潘帕斯草原的典型 Argiudolls 中进行了 14 次施锌田间试验。在 14 项试验中的 6 项中，锌肥增加了 GY。小麦 GY 对锌肥的响应范围为 300 至 949 kg ha ^–1。我们的 DTPA-Zn 阈值是通过田间试验确定的第一个在 Mollisol 中生长的小麦（1.03 mg kg ^-1，95% 置信区间为 0.87 至 1.23 mg kg ^-1）。该阈值大于先前报告的其他土壤类型的阈值。未来的研究应该通过结合不同的施肥量、来源、时间和位置来比较 Mollisol 上小麦的不同施锌策略。