Onobrychis viciifolia, known as sainfoin, is a perennial legume in the pea family. Originally from Europe and Asia, it is an introduced species in North America with a long history of cultivation as a forage crop. It was widely grown for centuries before its use declined in the mid-20th century as other crops gained popularity.
Identifying Sainfoin
Sainfoin is a distinct plant with an upright growth habit, reaching a height of one to three feet. Its most recognizable feature is its vibrant pink to purple flowers, arranged in dense, cone-shaped clusters called racemes. These flower heads can contain up to 80 individual blossoms.
The plant’s stems are coarse but succulent and grow from a branched root crown. The compound, pinnate leaves are composed of multiple small leaflets arranged in pairs along the stem. Each leaf has between 11 and 29 leaflets, giving the foliage a full appearance.
Agricultural Applications
Sainfoin’s primary agricultural role is as a forage crop for livestock like cattle and sheep. It is highly palatable and can be grazed directly in pastures or harvested for high-quality hay or silage. Its upright growth and excellent leaf retention make it well-suited for mechanical harvesting.
The plant’s value extends to apiculture, as its flowers produce large amounts of nectar, making them highly attractive to honey bees and other pollinators. Sainfoin is cultivated in some areas for honey production, and the resulting honey is high-quality with a distinct character.
Nutritional and Environmental Qualities
Sainfoin’s unique chemical composition provides benefits for animal health. It contains condensed tannins, compounds not present in high quantities in other legumes like alfalfa. These tannins bind to proteins in the rumen, preventing the rapid fermentation that leads to stable foam. This process mitigates the risk of bloat, a potentially fatal condition in ruminants.
Sainfoin is also a nutrient-dense feed with a high protein content that supports livestock growth. The condensed tannins contribute to a natural anthelmintic effect, helping to reduce the internal parasite load in animals. This quality decreases the reliance on chemical dewormers.
As a legume, sainfoin fixes atmospheric nitrogen in the soil, converting it into a form that plants can use. This natural fertilization reduces the need for synthetic nitrogen fertilizers, lowering both costs and environmental impact.
Cultivation and Growth
Sainfoin thrives in well-drained, alkaline soils with a neutral to high pH. It performs best in full sun and is well-suited to dry sites not prone to flooding. The plant is a good fit for areas that receive between 300 to 500 mm of annual precipitation.
While slower to establish than other forage crops, sainfoin is persistent once mature. Its deep taproot system is the reason for its drought resistance, allowing it to survive in regions with limited rainfall where other legumes might struggle.