Micronutrient-Doped Carbon Nanofibers Granulated with Secondary Nutrients: A Novel Approach to Improve Zn Translocation in Tomato (Solanum Lycopersicum L.)
Abstract
ABSTRACT Aim Zinc deficiency in soils severely limits crop productivity, mainly in Indian soils, particularly in Zn-sensitive crops like tomato. To address this challenge, a novel micronutrient-enriched carbon nanofiber granulated with secondary nutrients (M-CNF GSN) was developed to improve zinc delivery and evaluate its effects on Zn uptake and translocation in tomato. The M-CNF GSN system was designed based on the high surface area and functionalized surfaces of carbon nanofibers, which are expected to facilitate Zn delivery. Methods A pot culture experiment was conducted using acidic and zinc-deficient soil (pH 5.87; DTPA-extractable Zn: 0.79 ppm), comprising 14 treatments including a control, recommended dose of fertilizers (RDF), four zinc sulfate (ZnSO4) treatments, four M-CNF GSN treatments and four granulated secondary nutrient (GSN) treatments. Results Among them M-CNF GSN outperformed conventional ZnSO4, particularly at 1.25 kg Zn ha−1, achieving: 46.53 ppm Zn in shoots vs. 38.38 ppm in ZnSO4‑treated plants at 60 DAT, MCNF-GSN produced a significantly (p < .05) higher shoot-to-root Zn ratio (2.7-fold) than ZnSO4, indicating efficient systemic translocation, enhanced vegetative growth (111.70 cm plant height, 23 branches/plant) and accelerated flowering (20.7 days to first bloom). Hierarchical clustering revealed distinct Zn distribution patterns: M-CNF GSN treatments was associated with greater Zn accumulation in aerial tissues, while ZnSO4 led to root-bound accumulation (67.9 ppm in roots). Conclusion MCNF-GSN appeared to alleviate the negative effects associated with high calcium availability by stabilizing Zn2+ solubility and reducing fixation. This study indicates M-CNF GSN may become a sustainable technique for improving Zn use efficiency in Zn-deficient soils. Its dual function nutrient delivery and soil conditioning aligns with precision agriculture goals, offering a scalable solution to enhance crop resilience and yield. GRAPHICAL ABSTRACTThe diagram illustrates the process of combining MCNF and GSN to form MCNF GSN, which is then characterized. The MCNF GSN is applied to soil in pots, compared with ZnSO4 and a control. The growth of tomato plants is shown in three pots: MCNF GSN, ZnSO4 and Control. The MCNF GSN pot shows the tallest plant, indicating enhanced Zn efficiency. The ZnSO4 pot has a moderately tall plant, while the Control pot has the shortest plant. The text at the bottom reads, ′MCNF-GSN enhances Zn efficiency and growth in tomato under acidic, Zn-deficient soil.′.A diagram showing MCNF and GSN combination enhancing Zn efficiency in tomato growth under Zn-deficient soil.