Formulation of Dolomite-Supported and CNF-Translocated Multi-Micronutrients: An Advanced Fertilizer for Plant Growth

Abstract

A novel dolomite-supported carbon nanofiber (CNF) formulation, loaded with copper, zinc, molybdenum, and boron micronutrients (MO-BO–CNF/dolomite) has been developed as a micronano fertilizer. Dolomite serves not only as a substrate for CNF-growth but also as the source of secondary nutrients (calcium and magnesium), which are essential for plant health. CNFs efficiently translocate micronutrients from plant roots to shoots and leaves. The synthesized formulation is characterized using various physicochemical techniques, including transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, atomic absorption spectroscopy, and particle size analysis. The average CNF diameter is determined to be ∼107.2 nm, while XRD and X-ray photoelectron spectroscopies confirm the formation of metal oxides and CNFs. The formulation shows a surface charge of −19.4 mV, with a specific surface area of approximately 109 m²/g and total pore volume of 0.121 cc/g. Seed germination assays on Cicer arietinum with MO-BO–CNF/dolomite (1 mg/mL) over 6 days show 95% germination percentage. The 30-day plant growth experiment performed on C. arietinum plants using a dose of 1 g of the fertilizer per kg of soil reveals a significant improvement in the key growth parameters including the root and shoot lengths, biomass, and chlorophyll and protein contents in plants. The formulation improves not only the nutrient delivery efficiency but also the water-holding capacity of soil. MO-BO–CNF/dolomite-treated soil show a 7.8-fold rise in total nitrogen, underscoring its role in soil fertility. A relatively higher abundance of Bacillus sp., Acetobacter sp., and Rhizobiales facilitates nitrogen fixation in the MO-BO–CNF/dolomite treatment group. A controlled release of micronutrients offers a promising avenue for boosting modern agricultural productivity and sustainability.