The nitrogen use efficiency (NUE) is composed of the nitrogen uptake (NUpE) and nitrogen utilization efficiency (NUtE). The contribution of these components to overall NUE of sugar beet genotypes is unknown, as well as the reasons for genotypic variation. In 2018 and 2019, 6 genotypes were studied in field trials at three N levels (65, 120, 240 kg N ha⁻¹). The trials revealed only minor genotypic differences in N uptake and N uptake efficiency, but distinct genotypic differences in N utilization efficiency and NUE. The interaction between genotype and environment was negligible, i.e. differences between genotypes in NUE were independent of N management, and there was no genotypic adaptation to low N availability. Differences in NUE resulted rather from differences in sugar yield potential. This demonstrates that selection to high sugar yield potential will also promote NUE. It was concluded that a high sugar yield potential resulted from an assimilate partitioning towards high sugar yield, in combination with a low leaf mass to total dry mass ratio. There was evidence that lower leaf mass resulted in higher levels of leaf N content. If a higher leaf N content could be used to identify high yielding genotypes is unclear, but it was concluded that a high leaf mass is not a prerequisite for high sugar yields.

氮利用效率（NUE）由氮吸收量（NUpE）和氮利用效率（NUtE）组成。这些成分对甜菜基因型整体 NUE 的贡献以及基因型变异的原因尚不清楚。2018 年和 2019 年，在田间试验中在三个 N 水平（65、120、240 kg N ha ^-1）。试验揭示了氮吸收和氮吸收效率的基因型差异很小，但氮利用效率和 NUE 的基因型差异明显。基因型和环境之间的相互作用可以忽略不计，即 NUE 中基因型之间的差异与 N 管理无关，并且没有对低 N 可用性的基因型适应。NUE 的差异是由糖产量潜力的差异造成的。这表明对高糖产量潜力的选择也将促进 NUE。得出的结论是，高糖产量潜力是由向高糖产量分配的同化物分配以及低叶质量与总干质量比相结合造成的。有证据表明，较低的叶质量导致较高水平的叶 N 含量。