Potassium-based nanomaterials significantly enhance nutrient utilization efficiency and promote high crop yields†

Potassium (K) is an essential element for plant growth and development. It promotes various metabolic reactions and significantly improves the plant's uptake and utilization of nitrogen. This study conducted a comprehensive lifecycle investigation, comparing the long-term effects of soil-applied K₂SiO₃ nanoparticles (K₂SiO₃-NPs), K₁₈Mo₈O₃₃ nanoparticles (K₁₈Mo₈O₃₃-NPs), and K₂SO₄ at concentrations of 10–100 mg kg⁻¹ on soybean growth and nutritional components. Applying potassium-based nanomaterials at 20 and 50 mg kg⁻¹ concentration levels, respectively, showed similar or even better growth-promoting effects compared to traditional potassium fertilizers. Among them, the utilization rate of potassium-based nanomaterials has reached over 80%, significantly improving the utilization rate of traditional potassium fertilizers. Potassium-based nanomaterials also effectively enhanced the activity of soil peroxidase and catalase. It is worth noting that with increasing concentration of K₁₈Mo₈O₃₃-NPs, the soybean urease content continues to rise. In the treatment with potassium silicate, the urease content reached the maximum at 50 mg kg⁻¹. Besides, the starch, total protein, and fatty acids of soybean seeds treated with 50 mg kg⁻¹ K₂SiO₃-NPs and K₁₈Mo₈O₃₃-NPs were significantly increased. Therefore, using these two potassium-based materials can significantly enhance the efficiency of potassium fertilizer utilization. The study also revealed a significant positive correlation between the potassium content in different soybean organs and the amount of added potassium-based materials. As part of the nanotechnology agriculture strategy, these findings contribute to a better understanding of the transportation and distribution of potassium-based nanomaterials in soybeans, as well as their fate in soil ecosystems.