Red clover cultivars of Mattenklee type show higher yield and persistence than Ackerklee type

Specialised dairy farmers have increased interest in multi-year red clover (Trifolium pratense L.)-ryegrass (Lolium spp.) ley pastures because of their high productivity and protein concentration. However, the adoption of such mixtures is restricted because of the poor persistency of many red clover cultivars (cv.) currently used. Extending the duration of the clover ley would reduce costs for seeding and have positive effects on yield, carbon sequestration and soil biodiversity. We aimed to assess dry matter yield (DMY), persistence and nutritive value of four Mattenklee and four Ackerklee cv., and to investigate the underlying plant morphological traits. We conducted a four-year field experiment with red cloverryegrass mixtures, in combination with a short-term pot experiment. In the field, Mattenklees showed on average 42% higher production compared to Ackerklees in the third and fourth year. In the fourth year, Mattenklees had slightly lower digestibility and protein concentration compared to Ackerklees; however, the digestible dry matter and the protein yield were higher for Mattenklees. Both persistence and nutritive value of the different red clover cv. were closely correlated to stem length. For stem length there was close correlation between the pot and the field experiment, suggesting that this may be an important trait for plant breeding.