Nanotechnology in Crop Production: Applications, Evidence, Limitations and Future Directions

Abstract

Nanotechnology is increasingly being investigated as a means of improving nutrient delivery, crop establishment, plant growth, stress tolerance and crop protection while reducing losses associated with conventional agricultural inputs. This focused narrative review critically compares four original studies from Elsevier journals and positions their findings within a broader peer-reviewed evidence base. The focal studies evaluated a chitosan-silicon nanofertiliser in maize, a zinc oxide nanofertiliser in maize, chitosan nanoparticles in Capsicum species, and calcium-doped zinc oxide nanoparticles in maize and wheat. Across these studies, nanomaterials were applied through seed priming, foliar spraying or soil application and were evaluated using crop growth, photosynthetic pigments, antioxidant responses, yield attributes or pest infestation. Appropriately formulated and dosed materials improved selected outcomes: the chitosan-silicon nanofertiliser increased maize yield per plot by 43.4% at 0.08% and test weight by 45% at 0.04% compared with SiO2, while Ca-doped ZnO significantly improved measured growth parameters in maize and wheat. The review contributes an integrated formulation-route-response-safety framework that distinguishes promising crop responses from the evidence needed for agronomic recommendation. Its conclusions are relevant to crop researchers, input developers, regulators and extension systems, particularly where low nutrient-use efficiency, soil degradation and input costs constrain cereal and vegetable production. However, responses depend on particle composition, concentration, crop species, application route and environment, and the evidence remains dominated by short-duration or limited-location experiments. Multi-season field validation, nutrient-equivalent controls, residue and food-safety assessment, soil-microbiome studies, life-cycle analysis, economic feasibility and formulation-specific regulation are therefore required. Nanotechnology should be viewed as a promising component of integrated crop management rather than a universal substitute for conventional agronomic practices.