Response of Traditional Aromatic Rice (Oryza Sativa L.) Cultivars to Zinc Fertilization Strategies under Eastern Himalayan Region
Abstract
The present study aimed to evaluate the effect of zinc fertilization strategies on growth, yield, and nutrient uptake in two traditional aromatic rice cultivars, Tulaipanji and Kalonunia, under acidic soil conditions of North Bengal. The field experiment was conducted during the kharif seasons of 2022 and 2023 at Uttar Banga Krishi Viswavidyalaya, Pundibari, using a Split Plot Design with three replications. The main plot comprised two varieties, while the sub-plot included six zinc management treatments, involving combinations of soil-applied, foliar-applied, and nano zinc sources. Results revealed significant varietal differences, with Kalonunia consistently outperforming Tulaipanji in terms of plant height, number of tillers, chlorophyll index, grain yield, and nutrient uptake. Among zinc treatments, the integrated application of 2.5 kg Zn ha-1 as basal + 100 ppm nano Zn foliar at panicle initiation + 0.5% Zn foliar spray at grain filling (Z ) showed superior 3 performance across both years. Z₃ recorded the highest grain yield (2.77 t ha-1), grain number per panicle (121.69), and maximum uptake of nitrogen, phosphorus, potassium, and zinc in straw. This enhanced performance is attributed to improved zinc bioavailability and the synergistic action of multiple application timings and forms.
The findings emphasize the efficacy of integrated zinc management, particularly involving nano and foliar zinc application, in enhancing yield and nutritional quality of aromatic rice cultivars. Such strategies hold promises for sustainable crop production and combating micronutrient malnutrition in zinc-deficient regions.
Keywords
Download Options
Introduction
Rice is a staple food for the Asia-Pacific region, contributing approximately 21% of global energy and 15% of protein requirements (Sengupta et al., 2019). Among rice types, aromatic rice occupies a niche segment known for its aroma, fine grain, and superior cooking quality. West Bengal holds a rich diversity of traditional aromatic landraces, including Tulaipanji and Kalonunia, which are medium-grained types valued both domestically and for export potential (Mondal et al., 2011). Despite its importance, rice is nutritionally poor, particularly in micronutrients like zinc (Zn) andiron (Kumar et al., 2020). Micronutrient malnutrition or "hidden hunger" is widespread among resource-poor populations, largely due to low Zn bioavailability in cereal-based diets (Bouis and Saltzman, 2017). Zinc plays a vital role in numerous physiological and biochemical processes including enzyme activity, gene expression, photosynthesis, and stress tolerance (Hefferon, 2019). Moreover, higher Zn in rice straw is crucial for livestock nutrition in developing countries.
Agronomic biofortification, especially using Zn fertilizers, has emerged as a strategy to improve Zn content in grains, thereby enhancing both human and animal nutrition (WHO, 2002). Ahmed et al., 2021 also found tallest plant and maximum leaves of maize with soil application of 10 kg Zn ha-1. Recent advances advocate the use of zinc nanoparticles (ZnNPs), which offer controlled nutrient release, improved uptake efficiency, environmental safety, and economic benefits (Iqbal et al., 2020). Thus, ZnNPs hold promise for enhancing rice yield and nutritional quality, particularly in aromatic cultivars with export value. Based on above mentioned fact present study was undertaken at Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar during two consecutive kharif 2022 and 2023 to study the comparative response of zinc fertilization on traditional aromatic cultivars.
Conclusion
The present investigation demonstrated that varietal differences and zinc management practices significantly influenced the growth, yield, and nutrient uptake of aromatic rice under acidic soil conditions of North Bengal. Among the two tested cultivars, Kalonunia (V₂) consistently outperformed Tulaipanji (V₁) in terms of plant height, tiller number, chlorophyll index, grain yield, and nutrient uptake, highlighting its superior vegetative vigor and efficient resource use.
Zinc application strategies significantly enhanced growth parameters and yield components. The integrated treatment involving basal soil application of zinc along with foliar and nano zinc application at critical phenological stages (Z₃: 2.5 kg Zn ha⁻¹ as basal + 100 ppm nano Zn at panicle initiation + 0.5% Zn foliar spray at grain filling) was found to be the most effective. This treatment consistently recorded the highest grain yield, grain count panicle-1, and uptake of nitrogen, phosphorus, potassium, and zinc in both years of study. The effectiveness of Z₃ may be attributed to improved zinc bioavailability and synergistic effects of multiple application modes, enhancing enzymatic activity, spikelet fertility, and nutrient translocation during critical growth stages.
The findings underscore the potential of nano and foliar zinc fertilization, in conjunction with conventional soil application, to boost the productivity and nutritional quality of aromatic rice cultivars especially those like Kalonunia with strong genetic potential. These results support the use of integrated zinc management as a sustainable agronomic approach for improving rice yield and addressing zinc malnutrition in resource-poor regions.
