Comparative efficacy of Zn-EDTA and ZnSO4 in mitigating zinc deficiency in wheat for sustainable production

Zinc (Zn) deficiency in soils and crops poses a significant challenge to sustainable wheat production and human nutrition worldwide. Agronomic biofortification, enhancing cereal crops with zinc, is a rapid and effective strategy to address this issue. The present field study evaluated two zinc sources, zinc sulfate (ZnSO4·H2O, 33% Zn) and chelated zinc (Zn-EDTA, 5% Zn), for their effectiveness in enhancing yield and Zn concentration in Zn-responsive wheat varieties (Anmol-91, TD-1, NIA-Sarang, and NIA-Amber). The Zn treatments included: a control (no Zn), 13.2 kg Zn ha-1 as ZnSO4·H2O, and 0.125 and 0.25 kg Zn ha-1 as Zn-EDTA. Treatments were arranged in a randomized complete block split-plot design with three replications. Zinc application significantly improved wheat growth and yield traits compared to the control. However, no significant interaction was observed between treatments and varieties for agronomic parameters. Application of 0.25 kg Zn ha-1 as Zn-EDTA significantly increased plant height (by 4%), spike length (31%), number of spikelets per spike (7%), 1000-grain weight (12%), straw yield (10%), grain yield (10%), Zn concentration (16%), the phytic acid-to-zinc molar ratio (PA:Zn) (46%), and total absorbable zinc (TAZ) (87%) compared to the control. Furthermore, it significantly reduced phytic acid concentration in wheat grains by 37%. Soil Zn concentration also increased significantly (P 0.05), with the highest increase observed at 13.2 kg ha-1 ZnSO4 (125%) and the lowest with Zn-EDTA (95%) compared to the control. Among the wheat varieties evaluated, Anmol-91, NIA-Amber, and NIA-Sarang demonstrated the best performance.