Molybdenum fertilization enhances nodulation and seed yield of soybean (Glycine max L.) under field conditions

Efficient symbiotic nitrogen (N2) fixation in soybean is primarily driven by nodulation, which depends on effective inoculation and nutrient supply. Molybdenum (Mo) is a critical micronutrient that supports nitrogenase activity, the enzyme responsible for N2 fixation. This study, conducted in Telapayong, Arayat, Pampanga, Philippines, assessed the effect of varying Mo levels on soybean nodulation and yield. Treatments included a control, the recommended rate of fertilizer (RRF) (28-28-58 kg ha− 1 of N-P-K), and Mo applied at 31.5, 42.0, and 52.5 ppm. Results revealed that 52.5 ppm Mo significantly increased plant height at 30 and 60 days after sowing by 41.91 and 15.06% respectively, compared to control and RRF. Flowering was notably earlier with 42.0 ppm Mo. Nodulation traits, including nodule counts, formation rate, and biomass at R2 (full bloom) and R3 (pod development) stages improved significantly with 42.0 and 52.5 ppm Mo. The highest Mo level (52.5 ppm) resulted in a 43.62% in pod number (65.53 pods plant− 1) and an 88.33% in seed yield (2.26 t ha− 1) relative to the control. A strong positive correlation was found between nodulation traits and yield components, indicating that enhanced nodulation contributes to greater productivity. Overall, Mo at 52.5 ppm substantially improved nodulation and yield performance in soybean, highlighting its importance in nutrient management strategies for legume crops.