Second generation biofuels from non-edible biomass, such as bioethanol from cereal straw, are more sustainable than first generation biofuels such as bioethanol from maize seeds. Sustainability could be further enhanced by cultivating both cereals and legumes, such as pea, because legumes are enriched in nitrogen that fertilises later the cereals. Nitrogen-rich cereal straw should facilitate yeast fermentation to produce bioethanol because yeast needs nitrogen to grow. Agronomists Pellicano et al. tested wheat, barley, triticale and oat grown in intercrop with pea. They found indeed that pea improves the N content of the straw mixture.