Nitrogen (N) fertilization increases zinc (Zn) acquisition in cereal crops. However, little is known about the effects of N fertilization on grain Zn concentration in relation to availability of soil N and phosphorous (P) and root mycorrhizal colonization. The present study used a 12-year location-fixed field experiment with winter wheat grown at five N fertilization rates (0, 80, 160, 240 and 320 kg N ha⁻¹). The objective was to assess effects of phytoavailability of soil N and P and root mycorrhizal colonization on wheat Zn nutrition during three-year field measurements. Zinc concentration in wheat grains was increased with N fertilization in a linear-plateau fashion, and it reached the plateau of 30.3 ± 0.4 mg kg⁻¹ when soil mineral N (nitrate-N) levels were 8.5 ± 1.0 mg kg⁻¹ and above at maturity. Similarly, total shoot Zn uptake and Zn remobilization from vegetative tissues to grains were also increased significantly and then attained a plateau as the N rates increased. The enhancements in grain Zn concentration by N fertilization mainly occurred in the crease tissue, embryo and aleurone fractions of the grain. Long-term N fertilization was also associated with increases in root mycorrhizal colonization up to 8.8 ± 2.9 mg kg⁻¹ soil available mineral N at maturity. Shoot Zn uptake at maturity increased quadratically with the increase in shoot N uptake and root mycorrhizal colonization rate, whereas there was an inverse relationship between shoot Zn uptake and soil P availability. The results suggest that grain Zn concentration of wheat plants grown under long-term N fertilization was closely related to the soil mineral N status and showed clear increases with decreased soil available P concentration and improved root mycorrhizal colonization rates.

氮 (N) 施肥增加了谷类作物对锌 (Zn) 的吸收。然而，关于氮肥对谷物锌浓度的影响与土壤氮和磷（P）的有效性以及根部菌根定植的影响知之甚少。本研究使用了为期 12 年的定点田间试验，冬小麦以 5 种 N 施肥率（0、80、160、240 和 320 kg N ha ^-1）种植。目的是在三年的田间测量中评估土壤 N 和 P 的植物有效性以及根部菌根定植对小麦锌营养的影响。小麦籽粒中的锌浓度随着施氮而呈线性高原方式增加，当土壤矿物质 N（硝酸盐-N）水平为 8.5 ± 1.0 mg kg -1 时，它达到了 30.3 ± 0.4 mg kg ^{-1的平台。-1}及以上到期。类似地，从营养组织到籽粒的总芽锌吸收和锌再迁移也显着增加，然后随着氮速率的增加达到一个平台期。N施肥对籽粒Zn浓度的提高主要发生在籽粒的皱褶组织、胚和糊粉部分。长期施氮肥也与根菌根定植增加有关，高达 8.8 ± 2.9 mg kg ^-1成熟期土壤有效矿物氮。成熟期枝条锌吸收量随枝条吸氮量和根部菌根定植率的增加呈二次方增加，而枝条锌吸收量与土壤磷利用率呈负相关。结果表明，长期施氮的小麦籽粒锌含量与土壤矿质氮含量密切相关，且随着土壤速效磷浓度的降低和根部菌根定植率的提高而明显增加。