<p>Rice is a staple food of Asia and its productivity in zinc (Zn)-deficient acidic soils relies on sustainable Zn fertilization. A field experiment conducted over two consecutive years (2022–2023), to compare soil and foliar Zn fertilization strategies in acidic Zn-deficient Eastern Terai soils, India, focusing on grain yield, uptake, use efficiency and implications for nutritional biofortification of rice. Zinc fertilization significantly increased grain yield compared to control, with increments ranging from 7.2–10.0% in 2022 and 7.6–12.8% in 2023. Foliar application of 0.5% Zn-EDTA ha⁻¹ at 40 and 55 days after transplanting (DAT) recorded highest grain yield (4.90 and 5.01 t ha⁻¹, respectively). This yield was statistically similar to treatments receiving 1.5 kg Zn ha⁻¹ through soil applied Zn-EDTA or foliar spray of 0.5% Zn-EDTA ha⁻¹ at 55 DAT. The highest straw yield was also achieved with foliar application of 0.5% Zn-EDTA ha⁻¹ at 40 and 55 DAT (6.55 and 6.58 t ha⁻¹, respectively). Furthermore, this treatment recorded highest Zn content and uptake in both grain and straw, which was statistically comparable to the 0.5% Zn-EDTA ha⁻¹ at 55 DAT but significantly superior to soil application. Additionally, the 0.5% Zn-EDTA ha⁻¹ at 40 and 55 DAT significantly enhanced zinc use efficiency, partitioning and intake. Therefore, rice grown in Zn-deficient acidic soils in India’s Eastern Terai, foliar spray especially @ 0.5% Zn-EDTA at 40 and 55 DAT was a sustainable approach for improving rice productivity, grain Zn biofortification with potential benefits for human nutrition.</p> Graphical Abstract <p></p>