The absorption of NH₃ by the tomato canopy and the dynamics of this process in the plastic-shed vegetable production systems have not been reported. To quantify the contribution of the leaf absorption of ¹⁵NH₃, two field experiments were established to measure the amount of NH₃ translocated and recovered cumulatively (Experiment Ⅰ) and instantaneously (Experiment Ⅱ) by tomato canopy. Four applications of ¹⁵N-labeled urea as side dressing using a plastic tray method to simulate field management conditions. This experimental procedure prevented the uptake of N from the labeled urea by the roots. The results showed that total NH₃ loss accounted for 17.9 % of the N applied using the tray method, with average losses of 21.5 % and 14.3 % during the summer and winter growing seasons, respectively. The average canopy absorption of volatilized ¹⁵NH₃ was 12.2 % of the total N applied and the average canopy absorption rate of ¹⁵NH₃ reached to 2.81 % of the total ¹⁵N-urea applied. Additionally, an average of 44.13 % of the absorbed ¹⁵NH₃-N was transferred into the tomato fruit. Across four growth stages, whole-plant ¹⁵N accumulation increased gradually over the first three stages, with peak absorption occurring during the topping and pruning stage. Then, absorption rates decreased significantly during harvesting. NH₃ uptake by the tomato canopy was significantly more dynamic in summer than in winter. Our findings shed significant light on how NH₃ is taken up by the greenhouse tomato canopy and can contribute to improving the sustainability of agricultural systems.

尚未报道过番茄冠层对NH ₃的吸收以及该过程在塑料棚蔬菜生产系统中的动力学。为了量化叶片吸收^15种NH ₃的贡献，建立了两个田间试验，分别测量了番茄冠层累积（实验Ⅰ）和瞬时（实验Ⅱ）转运和回收的NH ₃的量。使用塑料托盘方法模拟^15种N标记尿素作为侧敷料的四种应用，以模拟田间管理条件。该实验步骤防止了根部从标记的尿素吸收氮。结果表明，总NH ₃托盘法施用的氮素损失量为氮的17.9％，夏季和冬季生长季节的平均损失量分别为21.5％和14.3％。的平均冠吸收挥发¹⁵ NH ₃是全氮施加的平均冠吸收率的12.2％¹⁵ NH ₃达到总量的2.81％¹⁵施加的N-脲。另外，平均44.13％的吸收的¹⁵ NH ₃ -N被转移到番茄果实中。跨越四个生长阶段，整个植物¹⁵氮的积累在前三个阶段逐渐增加，在摘心和修剪阶段出现峰值吸收。然后，在收获期间吸收率显着下降。夏季，番茄冠层对NH _3的吸收比冬季显着增加。我们的发现为温室番茄冠层如何吸收NH _3提供了重要启示，并有助于改善农业系统的可持续性。