Unravelling the effects of nano SiO ₂, nano TiO ₂ and their nanocomposites on Zea mays L. growth and soil health

Abstract

Amidst the challenges posed by climate change, exploring advanced technologies like nanotechnology is crucial for enhancing agricultural productivity and food security. Consequently, this study investigated the impact of nano SiO ₂ (nSiO ₂), nano TiO ₂ (nTiO ₂) and SiO ₂/TiO ₂ nanocomposites (NCs) on 30-day-old Zea mays L. plants and soil health at concentrations of 100 and 200 ppm. Results showed that nSiO ₂ and nTiO ₂ at 100 ppm and SiO ₂/TiO ₂ NCs at both concentrations, positively influenced plant growth, with the best stimulation observed at 200 ppm of SiO ₂/TiO ₂ NCs. Improved plant growth was associated with higher chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, rhizospheric N-fixing and phosphate solubilizing bacterial population and plant nutrient uptake. Additionally, treated plants exhibited increased cellulose and starch levels. Malondialdehyde (MDA) content was lower or similar to that of the control, except at 200 ppm of nTiO ₂-treated shoots. Antioxidant enzyme activities fluctuated, indicating physiological adjustments. Overall, 100 ppm of nTiO ₂ as well as nSiO ₂ and 100 and 200 ppm of SiO ₂/TiO ₂ NCs improved soil fertility and Z. mays growth, suggesting potential benefits for sustainable agriculture. The findings lay the foundation for more comprehensive investigations into the long-term fate of nanomaterials in soil and their intricate molecular-level interactions with Z. mays.