This chapter explores the potential of narrow-leaved plantain (ribgrass, Plantago lanceolata L.) to perform a range of roles in promoting more sustainable pasture-based livestock systems. The chapter begins by looking more broadly at the challenge of nitrogen losses from grazed pastures. This provides a context for first introducing plantain as a forage source. The chapter then explores recent research on the ways plantain affects nitrogen leaching. This functionality provides a way of mitigating nitrogen losses to air and water in intensive pasture-based livestock systems that is relatively simple to implement. This chapter summarises this and other uses of modern forage plantain and identifies scope for research relating to management for persistence, effects on animal health and milk composition and a better understanding of the biochemical mechanisms behind nitrogen cycle effects.