Legumes are an essential part of a strong and healthy grassland ecosystems. They form a symbiotic relationship with Rhizobium bacteria in which the bacteria fix nitrogen from the air into a plant-available form and share it with the legume. Clover also increases forage quality and quantity and helps to manage tall fescue toxicosis. In the past, the positive impact of clover on tall fescue toxicosis has always been thought to simply be a dilution effect, but new research from the USDA's Forage Animal Production Unit in Lexington shows that compounds found in red clover can reverse vasoconstriction that is caused by the ergot alkaloids in toxic tall fescue. The primary compound found in red clover is a vasodilator called "Biochanin A."