Effect of Soil and Foliar Zinc Fertilization on Growth and Fodder Yield of Cumbu Napier [CO (BN) 5] under Zinc-Deficient Soils of Tamil Nadu

          Zinc (Zn) is one of the most essential micronutrients required for the normal growth, development, and metabolic functioning of plants. Although needed in small quantities, its deficiency has become a constraint on agricultural productivity, particularly in tropical soils where intensive cultivation, low organic matter, and imbalanced fertilizer use have depleted  available zinc reserves (Alloway, 2008). In India, nearly 50% of cultivated soils are reported to be zinc-deficient, which adversely affects crop growth, yield, and quality (Singh et al., 2017).

          Zinc plays a vital role in several physiological and biochemical processes, including enzyme activation, auxin synthesis, chlorophyll formation, and protein metabolism (Broadley et al., 2007). In fodder crops, zinc deficiency not only limits vegetative growth and biomass production but also reduces the nutritional quality of the forage, indirectly influencing animal health and productivity (Kumar et al., 2021). Therefore, the balanced application of micronutrients such as zinc, along with macronutrient-based fertilizer recommendations, is essential for sustaining fodder yield and improving its nutritive value.

          Cumbu Napier [CO (BN) 5], a perennial hybrid between Pennisetum glaucum and Pennisetum purpureum, is widely cultivated for its high biomass potential, rapid growth rate, and palatability to livestock (Madesh et al., 2021). However, the productivity of this high-yielding fodder crop is greatly influenced by nutrient availability, particularly zinc, which regulates both growth and photosynthetic efficiency (Ramesh et al., 2020). While soil application of zinc improves the long-term nutrient status of the rhizosphere, foliar application offers a rapid correction of deficiency during critical growth stages (Dambiwal et al., 2017). Thus, a combined soil-and-foliar application of zinc may offer synergistic benefits by ensuring sustained and immediate nutrient supply.

          The present investigation was undertaken to study the effect of zinc fertilization through soil and foliar applications on the growth and yield attributes of Cumbu Napier [CO (BN) 5] grown under the zinc-deficient soils of Anaikatti, Coimbatore district, Tamil Nadu.

          The field experiment was conducted at a farmer’s holding in Anaikkatti village, Coimbatore district, Tamil Nadu, to evaluate the response of Cumbu Napier [CO (BN) 5] to different zinc fertilization levels. The subsequent laboratory analyses were carried out at the Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University (TNAU), Coimbatore.

          The experimental soil had a neutral pH (7.39), was non-saline (EC = 0.32 dS m⁻¹), and had a sandy clay loam texture. The soil contained medium organic carbon (0.56%), low available nitrogen (238 kg ha⁻¹), medium phosphorus (12.9 kg ha⁻¹), and potassium (261 kg ha⁻¹). The micronutrient status revealed zinc deficiency (0.72 mg kg⁻¹), while iron, manganese, and copper levels were sufficient.

          The experiment was laid out in a Randomized Block Design (RBD) with five treatments and four replications. Details of the treatments are given in Table 1. Slips of Cumbu Napier [CO (BN) 5] were planted at a spacing of 60 × 50 cm. All agronomic practices were followed as per TNAU recommendations. Foliar sprays were applied at 10-day intervals starting 30 days after planting (DAP). The plant height, number of tillers per plant, and SPAD values were measured at 40, 50, and 60 days after planting, respectively.

 Table 1. Treatment Details

Growth Attributes

          The growth attributes of Cumbu Napier [CO (BN) 5] fodder were significantly influenced by zinc fertilization (Table 2). Significant improvements were observed in plant height, number of tillers per clump, and SPAD values obtained at 40, 50, and 60 DAP, respectively. Among the treatments, the combined application of zinc through soil at 25 kg ZnSO₄ ha⁻¹  + 0.5 % foliar spray of ZnSO₄ recorded the maximum plant height of 320.8 cm, which was significantly superior to the soil treated with STCR-based NPK recommendations alone. Similarly, the number of tillers per plant was highest under the integrated zinc treatment (T₄) with a value of 35.4, indicating enhanced vegetative growth.

Table 2. Effect of zinc fertilization on growth parameters

          The SPAD values, which indicate relative chlorophyll content, also showed significant improvement with zinc application. The highest SPAD readings were recorded in T₄ (40.0, 47.2, and 49.5 at 40, 50, and 60 DAP, respectively), followed by T₅ and T₂, all of which showed a significantly better response than the STCR-based NPK recommendation alone (T₁).

          The increase in growth parameters may be attributed to zinc’s essential role in auxin synthesis, protein formation, and enzyme activation, which promote meristematic activity, internodal elongation, and chlorophyll development. Adequate zinc nutrition enhances photosynthetic rate and assimilates production, resulting in taller plants and greater tiller formation (Alloway, 2008). The improved growth under foliar + soil application also reflects better zinc mobility and utilization, ensuring nutrient availability during critical growth phases (Singh et al., 2019).

          Furthermore, zinc application promoted root proliferation, facilitating efficient uptake of water and other essential nutrients, thereby supporting overall plant growth (Prasad et al., 2016). The pronounced vegetative growth observed under combined zinc treatments aligns with the findings of Mir et al. (2025), who reported similar improvements in the growth and yield of fodder maize through zinc application. These results are also supported by Chaudhary et al. (2021), who observed that the vegetative growth of fodder crops was significantly enhanced by zinc fertilization under zinc-deficient soil conditions.

Yield Attributes

          Zinc fertilization significantly affected the yield attributes of Cumbu Napier fodder (Table 3). The highest green fodder yield was recorded in T₄ (53.4 t ha⁻¹ cut⁻¹), followed by T₅ (50.6 t ha⁻¹ cut⁻¹), T₂ (48.2 t ha⁻¹ cut⁻¹), and T₃ (44.8 t ha⁻¹ cut⁻¹), all of which were significantly superior to T₁ (42.6 t ha⁻¹ cut⁻¹). The dry fodder yield followed a similar trend, with T₄ producing 10.89 t ha⁻¹ cut⁻¹, significantly higher than the T₁ (8.35 t ha⁻¹ cut⁻¹) and other zinc treatments. The dry matter percentage was also highest in T₄ (20.4%), though differences among treatments were not statistically significant. The differences in green and dry fodder yield were significant (CD at 5% = 1.39 and 0.28 t ha⁻¹ cut⁻¹, respectively).

Table 3. Effect of zinc fertilization on growth parameters

          The substantial increase in yield under T₄ can be attributed to enhanced plant growth, higher chlorophyll content (SPAD values), and improved nutrient uptake and utilization efficiency driven by adequate zinc availability. Zinc enhances nitrogen metabolism, carbohydrate synthesis, and photosynthate translocation, which in turn increase biomass accumulation and fodder productivity (Rahman et al., 2020). The combined soil and foliar application ensures immediate nutrient absorption and sustained availability in the rhizosphere, providing continuous nutrient support throughout the growth period and enhancing green and dry fodder yields. Similar results were reported by Ramakrishna et al. (2022) in fodder maize, Nanda et al. (2025) in fodder oats, and Dambiwal et al. (2017) in sorghum, who all observed that combined zinc application significantly improved green fodder yield over individual application methods.

            The enhanced dry matter yield in T₄ can also be associated with improved water-use efficiency and stomatal regulation under adequate zinc nutrition (Cakmak, 2000), as well as better uptake of macronutrients such as nitrogen and phosphorus (Broadley et al., 2007). The overall findings indicate that combined soil and foliar zinc fertilization substantially improves growth, photosynthetic efficiency, and yield performance of Cumbu Napier fodder, indicating the importance of balanced micronutrient management for sustainable fodder production.

          The present study clearly demonstrated that zinc fertilization plays a pivotal role in enhancing the growth and yield performance of Cumbu Napier [CO (BN) 5]. Among the treatments, the combined application of soil test-based NPK + 25 kg ZnSO₄ ha⁻¹ + 0.5% ZnSO₄ foliar spray applied thrice at 10-day intervals (T₄) recorded the highest plant height, number of tillers, SPAD values, and green as well as dry fodder yield. The improvement in growth and yield attributes under this treatment could be attributed to the synergistic effect of soil and foliar zinc application, which ensured both immediate and sustained zinc availability, thereby enhancing chlorophyll synthesis, photosynthetic efficiency, enzymatic activities, and nutrient uptake.

          The findings confirm that combined zinc management not only improves biomass production but also enhances nutrient-use efficiency and plant growth. Hence, the combined soil and foliar application of zinc sulphate, along with soil-test-based NPK fertilization, is recommended as an effective and sustainable strategy to maximize fodder yield and maintain the nutritional quality of Cumbu Napier in zinc-deficient soils of Tamil Nadu.

Alloway, B. J. (2008). Zinc in soils and crop nutrition (2nd ed.). International Zinc Association & International Fertilizer Industry Association.

Broadley, M. R., White, P. J., Hammond, J. P., Zelko, I., & Lux, A. (2007). Zinc in plants. New Phytologist, 173(4), 677–702. https://doi.org/10.1111/j.1469-8137.2007.01996.x

Cakmak, I. (2008). Enrichment of cereal grains with zinc: Agronomic or genetic biofortification? Plant and Soil, 302(1–2), 1–17. https://doi.org/10.1007/s11104-007-9466-3

Chaudhary, M., Dwivedi, K., Sah, R., Gajghate, R., Ahmed, S., & Singh, K. (2021). Zinc biofortification of fodder oat (Avena sativa L.) through bioinoculant and synthetic fertilizers. Range Management and Agroforestry, 42(1), 181–185.

Dambiwal, D., Katkar, R. N., Kumawat, K. R., Hakla, C. R., Bairwa, B., Kumar, K., & Lakhe, S. R. (2017). Effect of soil and foliar application of zinc on sorghum (Sorghum bicolor (L.) Moench) yield, agronomic efficiency and apparent recovery efficiency. International Journal of Chemical Studies, 5(4), 435–438.

Kumar, B., & Ram, H. (2021). Biofortification of maize fodder with zinc improves forage productivity and nutritive value for livestock. Journal of Animal and Feed Sciences, 30(2), 149–158. https://doi.org/10.22358/jafs/135932/2021

Madesh, M., Kishore, K. R., Kumar, D. S., & Anitha, A. (2021). Nutrient intake, digestibility and rumen fermentation parameters in buffalo bulls fed Cumbu Napier (CO (BN) 5) fodder. Indian Journal of Animal Nutrition, 38(2), 195–200. https://doi.org/10.5958/2231-6744.2021.00031.1

Mir, N. H. (2020). Yield and quality assessment of fodder maize–legume intercropping systems with zinc fortification. Journal of Plant Nutrition. (In press)

Prasad, R., Shivay, Y. S., & Kumar, D. (2016). Interactions of zinc with other nutrients in soils and plants: A review. Indian Journal of Fertilisers, 12(5), 16–26.

Rahman, R., Sofi, J. A., Javeed, I., Malik, T. H., & Nisar, S. (2020). Role of micronutrients in crop production. International Journal of Current Microbiology and Applied Sciences, 8(11), 2265–2287.

Ramakrishna, C. H., Madhavi Lata, A., Murali, B., Madhavi, A., & Venkateswarlu, M. (2022). Yield and silage quality of fodder maize (Zea mays L.) as influenced by zinc fertilization. The Pharma Innovation Journal, 11(5), 1799–1802.

Singh, C., Singh, B., Satpal, P. K., Ankush, M., Gora, K., & Kumar, A. (2019). Micronutrient management for enhancing production of major fodder crops: A review. Forage Research, 45(2), 95–102.

Singh, S., & Singh, V. (2017). Productivity, quality and nutrient uptake by maize (Zea mays L.) as affected by sources and levels of zinc. Annals of Plant and Soil Research, 19(1), 95–99.