Introducing the Legumes

Three legumes with multiple benefits, Sainfoin, Birdsfoot Trefoil and Red Clover

Sainfoin being cut
Birdsfoot Trefoil © J. Engst
Red Clover - a valuable nectar source

Sainfoin (Onobrychis viciifolia) is a perennial legume herb with an erect growth habit, producing beautiful pink flowers. It is highly palatable to animals and has an excellent nutritional balance. It can be grazed, or fed as hay or silage. It thrives on alkaline soils, provides its own nitrogen and needs very little phosphate.  Sainfoin has a tap root that grows down to great depth, making the plant highly drought resistant. These roots are also able to draw up minerals from well below the top soil.

Sainfoin provides a superb forage for grazing animals and voluntary intake of sainfoin by cattle and sheep is 20% higher than for grass.  Unlike many other legumes, it is non-bloating and is known to have anthelmintic properties, so reducing the problems associated with livestock worms.  Sainfoin contains condensed tannins, and it is these that protect animals against bloat. Sainfoin has also been shown to increase protein absorption. This, combined with its other health benefits, mean that animals grazing sainfoin have very rapid liveweight gains, so young stock can be finished sooner and with very good carcass grades. Sainfoin is therefore extremely useful to low input and organic farmers. Yields can be very high at around 16t DM per hectare. 

Birdsfoot Trefoil (Lotus coniculatus) is perennial forage legume lasting for around 3-4 years. Like sainfoin it also contains tannins providing farmers with similar benefits in respect that it is bloat free and able to offer an alternative to anthelmintic drugs, of which many are becoming less effective. The plant has small brilliantly coloured yellow flowers which distinguish it from other trefoils. It parts of northern Europe it is known as ‘eggs and bacon’ and it can be found naturally on poor or soils with low fertility. There are a number of different varieties and naturally occurring forms with wide ranging growth habits within the the genus and this, again like sainfoin, offers plant breeders considerable potential for future development. Some erect, which are better for cutting for hay or silage and others with prostrate growth which is best suited to summer grazing. Most growth occurs during the summer and all forms have a deep tap root which are able to withstand drought. 

Birdsfoot trefoil offers ruminant animals a good source of protein and is usually grown in mixtures with grasses and other forage legumes. It will not tolerate competition from large legumes such as red clover or lucerne when these are dominant in a sward. When grown successfully birdsfoot trefoil can yield up to 14t DM per hectare in monoculture.

Red Clover (Trifolium pratense) is another short lived perennial lasting for between two and four years. It is normally used to produce silage, although it can be grazed occasionally. It is an erect and dominant plant that is best sown with aggressive grasses such as ryegrass. However, it may be included in more complex seed mixes but its inclusion rate must be low to counter its aggression. It grows on nearly all soils except very acidic ones. There are two distinct types of red clover: early and late flowering. The former starts spring growth earlier followed by another growth flush. The latter flowers 10-14 days later after its one main growth period. 

Red clover contains no tannins and so not able to offer the bloat free grazing or anthelminitic effects that sainfoin and birdsfoot trefoil can. However, its ease of establishment, drought resistance, high yield of up to 20t DM per hectare coupled with high reliability across a wide range of soil types has made it one of the most popular and important forage legumes in Europe. 

Modern plant breeding programmes during the last few decades have exploited and significantly increased diversity within the species and there are many varieties with good disease and pest resistance along with improved persistence. Sainfoin and birdsfoot trefoil have not yet been exploited to the same degree as red clover but many believe that further work will unearth tremendous agricultural benefits.