Assessment of Caucasian Clover (Trifolium ambiguum) for Swedish leys

Kura clover (Trifolium ambiguum M. Bieb.), also known as Caucasian clover, is a perennial forage legume with exceptional persistence, good winter survival and high potential for biological nitrogen fixation. Unlike red clover, it spreads through underground rhizomes, allowing stands to become denser and more persistent over time.

Although Kura clover has been studied internationally for many years, it has received little attention in Sweden. Slow establishment, limited seed availability and a lack of long-term field data have restricted its practical use. However, its persistence makes it an attractive species for long-term leys and grazing systems, where reduced reseeding and lower fertiliser requirements are important.

Research at SLU is evaluating the potential of Kura clover under Swedish conditions through long-term field experiments and studies of establishment, persistence, forage quality, disease resistance and species mixtures.

A demonstration stand of Kura clover was established at SLU in Umeå in 2017 to compare the long-term persistence of different forage legumes. While most other legumes have disappeared or declined substantially over time, the Kura clover stand remains vigorous and continues to expand through its underground rhizomes. The demonstration provides a striking example of the species' persistence under northern Swedish conditions and has been an important source of interest for farmers, advisors and researchers visiting the site.

SLU has established replicated field experiments at Rådde and Ås, together with a parallel trial in Finland, to evaluate the performance of Kura clover under Nordic conditions. The experiments compare several Kura clover varieties in mixtures with timothy and other forage legumes, assessing dry matter yield, persistence, botanical composition and forage quality.

The trials were established in 2023 and are now entering the period when Kura clover is expected to become increasingly productive. As the stands mature, the experiments will provide valuable information on long-term performance and identify varieties best suited to Swedish forage systems.

Parsons, D. (2026). Första och andra årets avkastning i vallblandningar med kuraklöver. Vallkonferens 2026, Rapport 39, SLU.

Louhisuo, A., Parsons, D., Termonen, M., Kykkänen, S. & Korhonen, P. (2025). Establishment and first-year yields of clover-grass leys with Caucasian clover (Trifolium ambiguum). Grassland Science in Europe, 30, 106–108.

Parsons, D., Bereyziat, N., Louhisuo, A., Kykkänen, S. & Korhonen, P. (2025). The effect of a companion legume on the establishment of Caucasian clover (Trifolium ambiguum) when sown with timothy. Grassland Science in Europe, 30, 275–278.