Graphene Oxide Nanoparticles Enhance Soil Biological Activity and Promote Growth and Nutrient Uptake in Ocimum basilicum L
摘要
Graphene oxide nanoparticles (GONPs), as emerging carbon-based nanomaterials with high surface area, active oxygen-containing functional groups, and strong ion-exchange capacity, have recently attracted considerable attention for their potential applications in sustainable agriculture. Nevertheless, their interactions with soil biological processes and plant physiological responses remain insufficiently understood, particularly regarding their dual role as both soil biostimulants and potential ecological stressors. In this study, the concentration- and time-dependent effects of GONPs on soil microbial dynamics, enzymatic activities associated with nutrient cycling, and plant physiological performance were comprehensively evaluated using basil as a model aromatic crop under controlled growth chamber conditions. Soils were treated with GONPs at concentrations of 0 (control), 200, 300, and 600 mg kg− 1 and incubated for 30, 60, and 90 days prior to plant cultivation. The results demonstrated that GONPs significantly stimulated soil biological activity in a dose- and exposure-dependent manner. At the highest concentration (600 mg kg− 1) after 90 days of incubation, the microbial population reached 1.6 × 109 cfu g− 1, corresponding to a 48-fold increase compared with the control. Dehydrogenase and urease activities increased by 6.9- and 3.4-fold, respectively, while alkaline and acid phosphatase activities increased approximately 1.9- and 1.86-fold. Plant physiological and nutritional traits were also markedly enhanced with increasing GONPs concentration. Total chlorophyll content, chlorophyll index, and carotenoids increased by 77%, 57%, and 3.2-fold, respectively, whereas antioxidant enzymes, including peroxidase and catalase, decreased approximately threefold. Furthermore, nutrient uptake was substantially improved, with nitrogen, phosphorus, and potassium concentrations increasing by 7-, 7.7-, and 5.8-fold relative to the control. Overall, the findings reveal that GONPs can positively regulate soil biochemical functioning and strengthen soil–plant interactions by stimulating microbial activity, enhancing nutrient cycling, and improving plant physiological performance. These results highlight the potential of GONPs as effective nano-enabled soil biostimulants for sustainable agricultural systems, while also emphasizing the importance of optimizing their concentration and exposure duration to ensure environmental compatibility and long-term agroecosystem sustainability.