Zheng Xu, Liu Jianguo, Cheng Zhibo, Sun Yingqiang, Li Luhua, Wang Jiaping
College of Agriculture, Shihezi University, Shihezi 832000, China.
The Key Laboratory of Oasis Eco-Agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi 832003, China.
Plants (Basel). 2024 Apr 10;13(8):1063. doi: 10.3390/plants13081063.
The cultivation of tiger nut ( L.) on marginal lands is a feasible and effective way to increase food production in Northern China. However, the specific influence of nitrogen fertilizer application on the growth dynamics, tuber expansion, overall yield, and nitrogen use efficiency (NUE) of tiger nuts cultivated on these sandy lands is yet to be fully elucidated. From 2021 to 2022, we conducted a study to determine the effect of N fertilizers on the leaf function morphology, canopy apparent photosynthesis (CAP), tuber yield, and NUE of tiger nut. The results indicate that the tuber yield and NUE are closely related to the specific leaf area (SLA), leaf area index (LAI), leaf nitrogen concentration per area (N), CAP, and tuber expansion characteristics. Notably, significant enhancements in the SLA, LAI, N, and CAP during the tuber expansion phase ranging from the 15th to the 45th day under the 300 kg N ha treatment were observed, subsequently leading to increases in both the tuber yield and NUE. Moreover, a maximum average tuber filling rate was obtained under the N300 treatment. These improvements led to substantial increases in the tuber yield (32.1-35.5%), nitrogen agronomic efficiency (NAE, 2.1-5.3%), nitrogen partial factor productivity (NPP, 4.8-8.1%), and nitrogen recovery efficiency (NRE, 3.4-5.7%). Consequently, 300 kg N ha of N fertilizers is the most effective dose for optimizing both the yield of tiger nut tubers and the NUE of tiger nut plants in marginal soils. Structural equation modeling reveals that N application affects the yield and NUE through its effects on leaf functional traits, the CAP, and the tuber filling characteristics. Modeling indicates that tuber expansion characteristics primarily impact the yield, while CAP predominantly governs the NUE. Above all, this study highlights the crucial role of N fertilizer in maximizing the tiger nut tuber yield potential on marginal lands, providing valuable insights into sustainable farming in dry areas.
在边际土地上种植虎坚果是增加中国北方粮食产量的一种可行且有效的方法。然而，氮肥施用对这些沙地种植的虎坚果的生长动态、块茎膨大、总产量和氮素利用效率（NUE）的具体影响尚未完全阐明。2021年至2022年，我们开展了一项研究，以确定氮肥对虎坚果叶片功能形态、冠层表观光合作用（CAP）、块茎产量和氮素利用效率的影响。结果表明，块茎产量和氮素利用效率与比叶面积（SLA）、叶面积指数（LAI）、单位面积叶氮浓度（N）、冠层表观光合作用和块茎膨大特性密切相关。值得注意的是，在300 kg N·ha处理下，在第15天至第45天的块茎膨大阶段观察到比叶面积、叶面积指数、单位面积叶氮浓度和冠层表观光合作用显著增强，随后导致块茎产量和氮素利用效率均增加。此外，在N300处理下获得了最大平均块茎充实率。这些改善导致块茎产量大幅增加（32.1% - 35.5%）、氮农学效率（NAE，2.1% - 5.3%）、氮偏生产力（NPP，4.8% - 8.1%）和氮回收效率（NRE，3.4% - 5.7%）。因此，300 kg N·ha的氮肥是优化边际土壤中虎坚果块茎产量和虎坚果植株氮素利用效率的最有效施用量。结构方程模型表明，施氮通过影响叶片功能性状、冠层表观光合作用和块茎充实特性来影响产量和氮素利用效率。模型表明，块茎膨大特性主要影响产量，而冠层表观光合作用主要决定氮素利用效率。最重要的是，本研究强调了氮肥在最大化边际土地上虎坚果块茎产量潜力方面的关键作用，为干旱地区的可持续农业提供了有价值的见解。
