This research was performed to investigate effect of growth facilitators on growth and functional characteristics of Onobrychis sativa Lam. in a factorial structure with a completely randomized design in greenhouse. Growth facilitators included potassium Nano silicate (0, 500 and 1000 mg/l), hydrogel of Boloorab (0, 10 and 30 g/kg), EM (0, 1 and 2%) and animal manure (0, 100 and 200 g/kg). At the end of growth, to investigate effect of growth facilitators on growth of O. sativa were measured fresh and dry weight of aerial organs and root, root length, plant height, volume root, aerial organs volume, establishment percentage, leaf area, photosynthesis rate, chlorophyll index, leaf relative water content, electrolyte leakage and curtain stability index. The results showed that the highest amount of dry weight (27. 89 g/pot), root length (28. 78 cm), plant height (70. 70 cm), root volume (7. 10 cm3), aerial organ volume (23. 50 cm3), establishment percentage (70. 80%), leaf area (4359. 92 cm2/pot), photosynthesis rate (14. 19 μ mol/m2 s) and chlorophyll index (7. 9) was observed in the treatment of animal manure 200 mg/kg. Other treatments also had desirable effects on growth and functional characteristics of O. sativa. Therefore, these treatments can be used in rangelands improvement and reclamation projects, and the conversion of abandoned dry farming lands and low-yield dry farming lands to pasturelands for the forage production.