Abstract The objectives of the present study were to assess and demonstrate the role of potassium fertilizer management on nitrogen use efficiency (NUE), and to select the most suitable set of NUE indicators. A series of six field experiments was conducted during 2009-2014. A principal trial factor was crop rotation (CR), potatoes - winter wheat - winter barley (1st CR/ lupine – cover crop/2nd CR). The experimental design was composed of four K rates (0, 80, 160, 240 kg K2O ha-1) and two N rates (120, 160 kg N ha-1). The marketable yield (MY) ranged from 20 to 49 Mg ha-1. The amount of K in tubers at harvest (Ka) was significantly associated with the MY. Ka, largely governed by the interaction between CR and K rate, was also linked to Partial Factor Productivity of fertilizer nitrogen (PFPN) and Agronomic Nitrogen Efficiency (ANE). The results suggest that the K rate should be oriented to the realization of a specific production strategy, depending on environmental factors (water shortage), and N use efficiency. It was documented that increased Ka might be a crucial factor for controlling N productivity, subsequently decreasing its rates. At the optimum K fertilizer rate, N rates can be significantly reduced.

中文翻译：

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钾肥作为马铃薯（Solanum tuberosum L.）氮可持续管理的驱动因素

摘要 本研究的目的是评估和证明钾肥管理对氮利用效率 (NUE) 的作用，并选择最合适的 NUE 指标集。2009 年至 2014 年期间进行了一系列六次现场试验。一个主要的试验因素是轮作（CR）、马铃薯 - 冬小麦 - 冬大麦（第 1 轮 CR/羽扇豆 - 覆盖作物/第 2 轮轮作）。实验设计由四个 K 比率（0、80、160、240 kg K2O ha-1）和两个 N 比率（120、160 kg N ha-1）组成。可销售产量 (MY) 范围为 20 至 49 Mg ha-1。收获时块茎中的钾含量 (Ka) 与 MY 显着相关。Ka 主要受 CR 和 K 率之间的相互作用控制，也与肥料氮的部分因子生产力 (PFP​​N) 和农艺氮效率 (ANE) 相关。结果表明，K 率应面向特定生产策略的实现，取决于环境因素（缺水）和 N 使用效率。据记载，增加的 Ka 可能是控制 N 生产力的关键因素，随后会降低其速率。在最佳钾肥施用量下，氮肥施用量可以显着降低。