The correct answer is Ficus.Ficus plants do not fix atmospheric nitrogen.Nitrogen fixation is the process by which nitrogen is taken from its molecular form (N2) in the atmosphere and converted into nitrogen compounds useful for other biochemical processes.Fixation can occur through atmospheric (lightning), industrial, or biological processes.A Nitrogen-fixing crop is a natural way to provide plant-adjusted Nitrogen without any industrial harm to nature.Nitrogen-fixing cover crops bring multiple benefits to farmers:Participate in Nitrogen fixationProtect soil from erosion by covering it or holding it in place with strong root systemsImprove soil fertility when used as green manureRetain soil moistureHelp in weed management with crop residuesServe as forage and grazing material for poultry and cattleAttract pollinators at the crop flowering time.Legumes are known as the best nitrogen-fixing plants and can be grown either as cash or cover crops.Some of the legume species are Lentils, Chickpea, Peanuts, Mung beans, pigeon pea, etc.The Ficus tree is a species of flowering plant.It is the official tree of Bangkok.