Agriculture has neglected silicon (Si) fertilization due to the widespread belief that soil has enough of Si and it is beneficial under any kind of biotic or abiotic stress, often neglecting its usefulness under optimum and stress-free conditions. A two-year field experiment was conducted to evaluate the effect of foliar spray of orthosilicic acid (OSA) on the growth, yield, nutrient content, and quality of fodder maize. The experiment was conducted in Zaid season at the Research Farm of Agronomy Section, ICAR-National Dairy Research Institute, Karnal, India. Seven treatments with different concentrations of OSA (0.05%, 0.10%, 0.15%, 0.20%, 0.25%, and 0.30%) were applied along with the recommended dose of fertilizer (RDF). RDF without OSA application was used as control. The results showed that OSA application significantly improved green fodder yield (GFY) and dry fodder yield (DFY). The concentration of 0.25% OSA resulted in the highest GFY (53.63 t ha− 1) and DFY (13.35 t ha− 1), which were 10.6% and 45.3% higher than the control, respectively. The application of OSA also positively influenced growth parameters such as crop growth rate (CGR), relative growth rate (RGR), dry matter accumulation (DMA), leaf:stem ratio, and physiological parameters including SPAD (chlorophyll content), relative water content (RWC%), and leaf area index (LAI). OSA foliar spray improved the nutrient content and uptake in fodder maize. Nitrogen (N%), potassium (K%), and calcium (Ca%) concentrations were significantly increased with OSA application, while phosphorus (P%) concentration remained unaffected. The uptake of N, P, K, and Ca was also significantly higher in the OSA-treated plots, with the 0.25% OSA treatment showing the highest nutrient uptake. OSA application recorded higher dry matter (DM%), crude protein (CP%), total ash (TA%), and lower neutral detergent fiber (NDF%), and acid detergent fiber (ADF%). Economic analysis revealed that OSA at 0.25% concentration resulted in the highest gross return, net return, and benefit-cost ratio (B:C), indicating its economic viability. Therefore, foliar spray of OSA, at 0.25% concentration, improved the growth, yield, nutrient content, and quality of fodder maize. This study highlights the potential of OSA as a beneficial foliar spray for enhancing production and quality of fodder maize.