Legumes like red clover and alfalfa are important for organic farming because they can fix nitrogen in the soil. A study in Northern Germany looked at how different legumes grown with grasses affected forage yield and nitrogen levels. They found that grass/legume mixtures had higher nitrogen fixation than mulched ones. Red clover and alfalfa produced more biomass and nitrogen than white clover. The type of legume and how it's managed can impact forage production and nitrogen levels in the soil, which is important for planning crop rotations.