Idaho is a major malt barley (Hordeum vulgare L.) producer in the United States. Production is concentrated in the semi-arid Snake River Plain region of southern Idaho. Irrigation and fertilizer N applications are two of the most important managed factors. Research was conducted at the University of Idaho Kimberly Research & Extension Center near Kimberly, ID, to determine yield, grain quality, and malt characteristics as affected by N application rate (0, 56, 112, and 168 kg N ha⁻¹) and final irrigation timing at Feekes 10.0 (boot; F10.0), Feekes 11.2 (soft dough; F11.2), and +7 d after Feekes 11.2 (+7F11.2). Irrigation termination at F10.0 resulted in decreased yields and unacceptable malt characteristics across N rates. Irrigation termination at F11.2 and +7F11.2 yielded 6,439 kg ha⁻¹ at a fertilizer N application of 56 kg N ha⁻¹, similar to higher N applications. Greater predicted yields up to 6,886 kg ha⁻¹ were calculated by regression analysis with applications up to 147 kg N ha⁻¹. Grain yield, protein, plumps, and test weights did not differ at any N rate for F11.2 or +7F11.2. Malt extract, free amino N, and diastatic power were similar for the F11.2 and +7F11.2 irrigations. Malt β-glucan content did not differ up to 56 kg N ha⁻¹ for any treatment, but reductions of up to 30 mg kg⁻¹ were measured at higher N rates for the +7F11.2 irrigation. Results warrant further investigations into increased N applications and provide evidence of the effects of irrigation cutoff timing and N for malt barley.

中文翻译：

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受氮和最终灌溉时间影响的大麦产量和麦芽特性

爱达荷州是美国主要的麦芽大麦（Hordeum vulgare L.）生产商。生产集中在爱达荷州南部半干旱的蛇河平原地区。灌溉和施氮肥是两个最重要的管理因素。爱达荷大学金伯利研究与推广中心在爱达荷州金伯利附近进行了研究，以确定受施氮量（0、56、112 和 168 kg N ha ^{-1 ）影响的产量、谷物品质和麦芽特性}) 和在 Feekes 10.0 (boot; F10.0)、Feekes 11.2 (软面团; F11.2) 和 Feekes 11.2 (+7F11.2) 后 +7 d 的最终灌溉时间。在 F10.0 时终止灌溉会导致产量下降和不同 N 速率的麦芽特性不可接受。在 F11.2 和 +7F11.2 终止灌溉，在施肥 56 kg N ha ^{-1 的情况下产生 6,439 kg ha -1 ，}类似于更高的施氮量。通过回归分析计算了高达 6,886 kg ha ^{-1的更大预测产量，施用量高达 147 kg N ha -1}. 对于 F11.2 或 +7F11.2，谷物产量、蛋白质、丰满度和容重在任何 N 比率下都没有差异。F11.2 和+7F11.2 灌溉的麦芽提取物、游离氨基氮和糖化能力相似。^{对于任何处理，麦芽 β-葡聚糖含量在高达 56 kg N ha -1}时没有差异，但在 +7F11.2 灌溉的较高 N 速率下测量到高达 30 mg kg ^{-1的减少量。}结果值得进一步研究增加氮的应用，并提供灌溉截止时间和氮对麦芽大麦的影响的证据。