Recent interests in improving agricultural production while minimizing environmental footprints emphasized the need for research on management strategies that reduce nitrous oxide (N₂O) emissions and increase nitrogen-use efficiency (NUE) of cropping systems. This study aimed to evaluate N₂O emissions, annualized crop grain yield, emission factor, and yield-scaled- and NUE-scaled N₂O emissions under continuous spring wheat (Triticum aestivum L.) (CW) and spring wheat–pea (Pisum sativum L.) (WP) rotations with four N fertilization rates (0, 50, 100, and 150 kg N ha⁻¹). The N₂O fluxes peaked immediately after N fertilization, intense precipitation, and snowmelt, which accounted for 75–85% of the total annual flux. Cumulative N₂O flux usually increased with increased N fertilization rate in all crop rotations and years. Annualized crop yield and NUE were greater in WP than CW for 0 kg N ha⁻¹ in all years, but the trend reversed with 100 kg N ha⁻¹ in 2013 and 2015. Crop yield maximized at 100 kg N ha⁻¹, but NUE declined linearly with increased N fertilization rate in all crop rotations and years. As N fertilization rate increased, N fertilizer-scaled N₂O flux decreased, but NUE-scaled N₂O flux increased non-linearly in all years, regardless of crop rotations. The yield-scaled N₂O flux decreased from 0 to 50 kg N ha⁻¹ and then increased with increased N fertilization rate. Because of non-significant difference of N₂O fluxes between 50 and 100 kg N ha⁻¹, but increased crop yield, N₂O emissions can be minimized while dryland crop yields and NUE can be optimized with 100 kg N ha⁻¹, regardless of crop rotations.

中文翻译：

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减少氮素含量不同的旱地轮作过程中的一氧化二氮排放量并优化氮利用效率

在改善农业生产同时最大程度减少环境足迹的近期兴趣中，强调了对管理策略的研究需求，该策略应减少一氧化二氮（N ₂ O）排放并提高种植系统的氮利用效率（NUE）。本研究的目的是评估Ñ ₂ O排放，年作物产量，排放因子，和产量按比例调整和NUE缩放Ñ ₂ O排放下连续春小麦（小麦L.）（CW）和春小麦豌豆（以4 N的施肥速率（0、50、100和150 kg N ha ^-1）旋转番茄（Pisum sativum L.）（WP ）。N ₂施氮，强降雨和融雪后，O通量立即达到峰值，占全年总通量的75-85％。在所有轮作和年份中，累积的N ₂ O通量通常随着氮肥施用量的增加而增加。在所有年份中，0 kg N ha ^-1的年均农作物产量和NUE均高于连续水，但在2013年和2015年趋势以100 kg N ha ^-1逆转。作物产量在100 kg N ha ^-1最高，但在所有轮作和年份中，NUE均随着氮肥施用量的增加而线性下降。随着氮肥施肥量的增加，氮肥规模的N ₂ O通量减少，但NUE规模的N ₂无论作物轮作如何，O通量在所有年份中均呈非线性增长。产量标度的N ₂ O通量从0 kg N ha ^-1降低到50 kg N ha ^-1，然后随着氮肥施用量的增加而增加。由于N个非显著差的₂ 50和100公斤氮公顷O之间通量^-1，但增加作物产量，N ₂ O排放，可以同时旱地作物产量最小化，并且可以NUE用100公斤氮公顷被优化^-1，不论轮作。