Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that is native to Caucasia, is extremely persistent in North America, but its performance has not been adequately evaluated in Europe. The objective of this research was to compare forage yield and nutritive value of Kura clover to lucerne (Medicago sativa L.), red clover (Trifolium pretense L.) and white clover (Trifolium repens L.) at two locations in Poland. All clover stands thinned markedly by spring of the second production year because of infection by Sclerotinia crown and stem rot, but lucerne stands remained dense and this legume produced the highest total yield over 3 or 4 production years. Kura clover yields of 7.2–8.3 Mg ha⁻¹ were second to lucerne by the third production year but long-term performance was diminished by stand thinning. Kura clover and white clover had lower fiber concentrations and greater protein concentrations and forage digestibility than red clover and lucerne. Kura clover can be a source of high-quality forage in Europe, but cannot be recommended for use in areas with known Sclerotinia trifoliorum presence until resistance to this pathogen is developed.

Intercropping cereal crops with perennial legumes for forage has been demonstrated as a means to improve nutritive value compared to cereal crops alone. Our objective was to determine whether sowing winter rye (Secale cereale L.) or winter triticale (x Triticosecale Wittmack) into living Caucasian clover (Trifolium ambiguum M. Bieb.) improves yield or nutritive value compared to monoculture cereal crop forage in northern Europe. The experiments were conducted near Mochełek and Falęcin, Poland. In autumn 2010 and 2011, winter rye was sown into existing Caucasian clover or in monoculture at Mochełek, and winter triticale was sown into Caucasian clover or in monoculture at Falęcin, with monoculture clover as a third crop treatment at both locations. The following spring, first harvest of forage from the three crop treatments was taken at two maturities: when monoculture cereals reached heading (BBCH 51) or grain milk stage (BBCH 71), and two additional harvests were taken from mixture plots and monoculture clover before autumn. First harvest forage yields of mixtures were similar to monoculture cereal at Falęcin, less than monoculture cereal at Mochełek, and greater than monoculture clover at both locations. Full season forage yields of mixtures were greater than both monoculture cereal and clover crops at both locations. The proportion of clover in mixtures was 20–31% in the first harvest, resulting in slightly lower neutral detergent fiber concentrations than in monoculture cereal crop at Falęcin, but no improvement in nutritive value at Mochełek. By spring 2012, most Caucasian clover had died from Sclerotinia trifoliorum infection at both locations, so forage was not harvested in the second year of the experiment. Although total season forage yields were greater for mixtures than for either monoculture cereal or Caucasian clover, this system cannot be recommended for northern Europe because of failure for Caucasian clover to persist.