Nanoparticle-Driven Modulation of Soil Fertility and Plant Growth: Evaluating Fe2O3 and CuO Nanofertilizers in Sandy Loam Soils

The excessive use of conventional fertilizers has led to low nutrient-use efficiency and significant environmental challenges. To address these limitations, this study aimed to evaluate the effects of Fe2O3 and CuO nanoparticles (NPs) as potential nanofertilizers, on the soil chemical composition, nutrient fractionation, enzyme activity, and Lepidium sativum L. growth. The results of the study showed that Fe2O3-NPs improved nitrogen bioavailability and enhanced plant biomass, particularly at low to moderate doses. CuO-NPs, in contrast, reduced nitrogen and phosphorus mobility and showed phytotoxic effects at high concentrations. Enzyme activity was suppressed at high NP levels, likely due to oxidative stress. Nutrient fractionation revealed the increased immobilization of phosphorus and the moderate mobilization of potassium and copper, depending on NP type. Based on the results, Fe2O3-NPs show potential as a nanofertilizer for enhancing soil fertility and plant growth in sandy loam soils, whereas CuO-NPs require caution due to toxicity risks. Future research should focus on long-term environmental impact, optimal NP concentrations, and their interaction with soil microbial communities.