Abstract:
The recent advancement in the field of nanotechnology has accompanied the assessment of potential effects of nanoparticles on soil health and plants. This study focused on assessing the effects of TiO2 nanoparticles on nutrient availability, growth of Triticum aestivum and microbial population. For this purpose, TiO2 nanoparticles were synthesized and characterized through Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The particle size was <20 nm with anatase phase in dominance. Pot experiment was carried out with three soils having different pH (6.1, 7.3, and 8.4). The plants were exposed to different concentrations (0, 20, 30, 40, and 50 mg kg-1) of TiO2 nanoparticles till crop maturity. Chlorophyll content was measured twice a week. In soil with pH 7.3, at 50 mg kg-1 of TiO2 nanoparticles, dry root and shoot biomass increased up to 1.3 and 2-fold respectively, and root and shoot length increased up to 1 and 1.3-fold respectively as compared to the control. Chlorophyll content increased up to 0.7-fold in soil having pH 7.3 at 50 mg kg-1 of TiO2 nanoparticles. In soil having pH 6.1, sodium and potassium concentrations increased up to 0.9-fold and 0.7-fold in root; 0.9-fold and 0.8-fold in shoot respectively at 50 mg kg-1 of TiO2 nanoparticles. In soil having pH 7.3, available phosphorus (P) and total phosphorus (P) increased up to 2.4-fold and 0.8-fold in root; 0.8-fold and 0.7-fold in shoot respectively upon application of 50 mg kg-1 of TiO2 nanoparticles. Aluminum (Al), calcium (Ca), iron (Fe), magnesium (Mg), copper (Cu), zinc (Zn), and total nitrogen (N) increased up to 2.4-, 3.1-, 0.9-, 2.3-, 3.1-, 1.7-, 1.2-folds respectively in root; 3.1-, 4.6-, 3.2-, 3.2-, 2.1-, 3.6-, 0.9-folds respectively in shoot at 40 mg kg-1 of TiO2 nanoparticles. A significant increase in the concentration of Al, Ca, Cu, Fe, Mg, and Zn in soil was observed at 50 mg kg-1 at soil pH 7.3. However, at pH 8.4, nitrate-N increased up to 0.8-fold in soil at 50 mg kg-1 of TiO2 nanoparticles. Maximum nutrient uptake per plant for all nutrients was observed in soil with pH 7.3 at 50 mg kg-1 of TiO2 nanoparticles. Microbial population and biomass decreased slightly upon application of TiO2 nanoparticles. These significant improvements related to growth upon TiO2 nanoparticles application can be attributed to improved acquisition of nutrients by the wheat plants from the spiked soils.
