Phosphorus and Silicon Interactions in Plants: The Role of Biogenic Nano‐Silicon and Its Composites on Silicon and Phosphorus Nutrition of Maize and Rice Plants

ABSTRACT Background and Aims The use of phosphorus (P) fertilizers reduces the availability of silicon (Si) in soils, especially in crops such as rice and maize that have a high Si demand. This study conducted three experiments to examine P–Si interactions, Si's impact on P uptake, and the potential of Nano‐Si and two types of Nano‐Si (NanoLig‐Si and NanoSel‐Si) as alternative Si sources. Methods Nano‐Si materials were characterized using scanning electron microscopy (SEM), XRD, and Fourier transform infrared (FTIR). Three experiments were conducted: (1) the effect of increasing P levels on Si concentration in barley and wheat; (2) the impact of Nano‐Si and Na‐Silicate on P and Si nutrition in maize; and (3) the influence of Nano‐Si, NanoLig‐Si, and NanoSel‐Si on P and Si nutrition in rice under soil and hydroponic conditions. Results Applied P reduced the Si concentration in barley from 5.53 to 2.18 g kg −1 and in subsequently grown wheat from 9.07 to 5.05 g kg −1 . Both Si sources significantly increased P concentrations, whereas only Nano‐Si treatment had a positive effect on the Si concentration of maize. In soil, Si treatments did not affect rice P concentrations. In hydroponics, P increased with Nano‐Si and low composite doses, whereas Si increased with Na‐silicate and high doses of NanoSel‐Si and NanoLig‐Si. Conclusions These results reveal crop‐ and system‐specific P–Si interactions. Although high P reduced Si uptake in barley and wheat, Si sources enhanced P uptake. Nano‐Si materials were most effective in boosting P and Si uptake in soilless systems.