Nitrogen pollution from intensified agricultural production is a major driver of ecosystem degradation, contributing to aquatic eutrophication and global greenhouse gas emissions. Incorporating nitrogen-fixing leguminous intercrops into agricultural systems is an increasingly popular management strategy to mitigate those negative impacts. Using a perennial grainlegume intercropped agricultural system, this study aims to evaluate the potential for leguminous nitrogen fixers to support biomass yield of a well-developed perennial wheat, intermediate wheatgrass (Thinopyrum intermedium). The results of this study identified trends in improved forage quality, land use efficiency, and nitrogen fixation rates within the intermediate wheatgrass- alfalfa intercrop system. Findings also show that both white clover and alfalfa fix sufficient nitrogen to balance intermediate wheatgrass nitrogen uptake.