School of Agricultural and Veterinarian Sciences, São Paulo State University (Unesp), Via de Acesso Prof. Paulo Donato Castellane S/N, Jaboticabal, 14884-900, Brazil.
Sci Rep. 2023 Oct 7;13(1):16929. doi: 10.1038/s41598-023-44301-5.
Potassium (K) deficiency in maize plants damages the nutritional functions of K. However, few studies have investigated the influence of K on C:N:P stoichiometry, the nutritional efficiency of these nutrients, and whether the mitigating effect of Si in plants under stress could act on these nutritional mechanisms involved with C, N, and P to mitigate K deficiency. Therefore, this study aimed to evaluate the impact of K deficiency in the absence and presence of Si on N and P uptake, C:N:P stoichiometric homeostasis, nutritional efficiency, photosynthetic rate, and dry matter production of maize plants. The experiment was conducted under controlled conditions using a 2 × 2 factorial scheme comprising two K concentrations: potassium deficiency (7.82 mg L) and potassium sufficiency (234.59 mg L). These concentrations were combined with the absence (0.0 mg L) and presence of Si (56.17 mg L), arranged in randomized blocks with five replicates. Potassium deficiency decreased stoichiometric ratios (C:N and C:P) and the plant's C, N, and P accumulation. Furthermore, it decreased the use efficiency of these nutrients, net photosynthesis, and biomass of maize plants. The results showed that Si supply stood out in K-deficient maize plants by increasing the C, N, and P accumulation. Moreover, it decreased stoichiometric ratios (C:N, C:P, N:P, C:Si, N:Si, and P:Si) and increased the efficiencies of uptake, translocation, and use of nutrients, net photosynthesis, and dry matter production of maize plants. Therefore, the low nutritional efficiency of C, N, and P caused by K deficiency in maize plants can be alleviated with the supply of 56.17 mg L of Si in the nutrient solution. It changes C:N:P stoichiometry and favors the use efficiency of these nutrients, which enhances the photosynthesis and sustainability of maize.
钾（K）缺乏会损害玉米植株的营养功能。然而，很少有研究探讨 K 对 C:N:P 化学计量、这些养分的营养效率以及 Si 在缓解胁迫下植物的作用是否可以作用于涉及 C、N 和 P 的这些营养机制，以缓解 K 缺乏。因此，本研究旨在评估在不存在和存在 Si 的情况下 K 缺乏对 N 和 P 吸收、C:N:P 化学计量平衡、营养效率、光合作用和玉米植株干物质生产的影响。该实验在控制条件下进行，采用 2×2 析因设计方案，包括两个 K 浓度：低钾（7.82 mg L）和钾充足（234.59 mg L）。这些浓度与 Si 的有无（0.0 mg L 和 56.17 mg L）结合，随机区组排列，重复五次。低钾降低了化学计量比（C:N 和 C:P）和植物的 C、N 和 P 积累。此外，它降低了这些养分的利用效率、净光合速率和玉米植株的生物量。结果表明，Si 供应在低钾玉米植株中表现突出，增加了 C、N 和 P 的积累。此外，它降低了化学计量比（C:N、C:P、N:P、C:Si、N:Si 和 P:Si），提高了养分吸收、转运和利用、净光合速率和玉米植株干物质生产的效率。因此，K 缺乏导致玉米植株中 C、N 和 P 的营养效率低下，可以通过在营养液中供应 56.17 mg L 的 Si 来缓解。它改变了 C:N:P 化学计量，有利于这些养分的利用效率，增强了玉米的光合作用和可持续性。
