Microcosm based bio-efficacy evaluation of biologically produced nano-Zn–Fe fertiliser

Chemical fertilisers are a significant component of agricultural inputs needed to achieve the highest possible yield and productivity. Fertilisers, on the other hand, change the nutrient balance and health of the soil. Furthermore, because of its low usage efficiency, this widespread use has a negative impact on ecosystems. In this study, nano-Zn–Fe fertiliser was synthesised in a microbial bioreactor and its key properties were determined, including actual particle size, elemental composition, zeta potential, and bioactive content. A microcosm plant bioassay system developed in-house was used to assess the bio-efficacy of biologically generated nano-Zn–Fe fertiliser. The fertiliser was applied to maize (at a rate of 1500 μ g g −1 seeds) using a polymer-based seed coating technique and compared to commercial bulk and nano-fertilisers. The results indicate that nano-Zn–Fe fertiliser considerably improves seed germination, plant growth, and nutrient uptake in plants when compared to controls (polymer and feedstock material coated seeds) and commercial goods (bulk and nano-fertilisers). Additionally, we calculated the lead content of the plant system to verify that the produced material is non-toxic in accordance with global fertiliser permissible limit standards. As a result, nano-Zn-Fe fertilisers may be a more viable option for supplying an alternative source of zinc and iron fertilisers to balance global agricultural productivity constraints.