Abstract The agronomic efficiency of conventional silicon (Si) fertilizers is frequently limited by their low bioavailability in soil. Consequently, nano-silica (nano-Si) has gained increasing attention as a sustainable alternative due to its enhanced availability and potentially superior physiological effectiveness in plants. The present study aimed to synthesize nano-Si from rice husk (RH), and its effects on growth, oxidative stress responses, and nutrient status of durum wheat. Nano-Si was characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). SEM observations showed a hierarchical structure consisting of micro-scale porous frameworks formed by agglomerated nano-sized primary particles lower than 80 nm, while largely preserving the native siliceous architecture. FTIR and XRD analyses confirmed that the material was predominantly amorphous Si with characteristic Si-O-Si functional groups. A pot experiment was conducted in which nano-Si and sodium silicate were applied at rates of 0, 25, 50, and 100 mg kg − 1 to wheat plants grown under drought conditions. Applied Si did not significantly influence total dry weight; however, grain yield responded strongly to nano-Si, with the highest yield recorded at 25 mg kg − 1 . This treatment also resulted in higher chlorophyll content and relative water content, along with lower H 2 O 2 accumulation and membrane permeability, and enhanced antioxidant enzyme activities, particularly ascorbate peroxidase. In contrast, sodium silicate produced weaker physiological responses and was associated with increased H 2 O 2 levels. Nano-Si application increased plant Si and P concentrations. Nano-Si outperformed Na-Si in improving grain yield, photosynthesis, water relations, and oxidative stress tolerance in wheat, indicating its potential as a sustainable Si fertilizer.
Ozturk et al. (Fri,) studied this question.