Nitrogen (N) management is important for farmers to balance production, economic and environmental performance of their farms. This is particularly true in the intensive cropping systems of northwest Europe where tuber, root and bulb crops are cultivated in rotation with cereal crops and where an intensive livestock sector makes organic manures available at low cost for arable farmers. Here, we build upon a large database of farmer field data to assess mineral and organic fertiliser N performance, and its determinants, for the major arable crops in the Netherlands according to the guidelines provided by the EU N Expert Panel (EUNEP). The EUNEP framework quantifies N outputs and N inputs, N-use efficiency as the ratio between N outputs and N inputs (NUE in kg N output harvested per kg N input) and N surplus as the difference between N inputs and N outputs (Ns in kg N ha⁻¹). As a next step, biophysical and crop management determinants of N performance were explored using data from different years, soil types and N management in relation to the amount, source, time and method of N applied. NUE was on average ca. 0.95 kg N kg⁻¹ N for seed potato, sugar beet and spring onion, 0.87 kg N kg⁻¹ N for ware potato, ca. 0.80 kg N kg⁻¹ N for starch potato and winter wheat and, ca. 0.70 kg N kg⁻¹ N for spring barley, all within or above the target range of 0.50–0.90 kg N kg⁻¹ N proposed by the EUNEP. Ns was on average below the EUNEP threshold of 80 kg N ha⁻¹ for all crops: 78 kg N ha⁻¹ for ware potato and winter wheat, ca. 70 kg N ha⁻¹ for starch potato, ca. 50 kg N ha⁻¹ for spring barley, ca. 25 kg N ha⁻¹ for sugar beet and spring onion and less than 20 kg N ha⁻¹ for seed potato. Although average Ns was below 80 kg N ha⁻¹, ca. 40% of the ware potato, starch potato and winter wheat fields analyzed had Ns above this threshold. The relatively high NUE combined with high Ns for most crops are the result of high N outputs (yields) combined with high N application rates. Moreover, high NUE and small Ns were mostly associated with smaller N application rates and with the use of mineral fertilisers instead of organic fertilisers, while there were no clear relationships between the two indicators on the one hand with N application time or method on the other. We conclude NUE and Ns were on average within the EUNEP target range for most crops, but there are still a considerable number of under-performing farms where increases in NUE and reductions in Ns are possible through reducing N inputs. We recommend future research to assess the benefits of organic fertilisers from a circularity perspective at regional and national levels and to cross-validate the crop-specific results presented in this study with NUE assessments at cropping systems level.

氮 (N) 管理对于农民平衡农场的生产、经济和环境绩效非常重要。在西北欧的集约化种植系统中尤其如此，在那里块茎、块根和球茎作物与谷类作物轮作种植，集约化畜牧部门为耕种农民提供低成本的有机肥料。在这里，我们建立在一个大型农民田间数据数据库的基础上，根据欧盟 N 专家小组 (EUNEP) 提供的指导方针，评估荷兰主要可耕作物的矿物和有机肥料 N 性能及其决定因素。EUNEP 框架量化了 N 个输出和 N 个输入，^-1 )。下一步，利用不同年份、土壤类型和氮管理与施氮量、来源、时间和方法相关的数据，探索了氮性能的生物物理和作物管理决定因素。NUE 平均约为。 种薯、甜菜和葱为0.95 kg N kg ^-1 N，制土豆为 0.87 kg N kg ^-1  N，约。0.80 kg N kg ^-1 N 用于淀粉马铃薯和冬小麦，约 0.70 kg N kg ^-1 N 春大麦，均在或高于 EUNEP 提出的 0.50–0.90 kg N kg ^-1 N目标范围内。所有作物的Ns 平均低于 EUNEP 阈值 80 kg N ha ^-1：78 kg N ha ^-1用于加工马铃薯和冬小麦，约 70 kg N ha ^-1用于淀粉马铃薯，约。50 kg N ha ^-1春大麦，约。25 kg N ha ^-1用于甜菜和葱，小于 20 kg N ha ^-1用于种薯。尽管平均 Ns 低于 80 kg N ha ^-1，约 分析的 40% 的陶器马铃薯、淀粉马铃薯和冬小麦田的 Ns 高于此阈值。对于大多数作物而言，相对较高的 NUE 与较高的 Ns 相结合是高氮输出（产量）与高施氮率相结合的结果。此外，高 NUE 和小 Ns 主要与较小的施氮量和使用矿物肥料而不是有机肥有关，而这两个指标一方面与施氮时间或施氮方法之间没有明确的关系. 我们得出的结论是，大多数作物的 NUE 和 Ns 平均在 EUNEP 目标范围内，但仍有相当多表现不佳的农场，通过减少 N 投入可以增加 NUE 和减少 Ns。