Does the variety of Lolium perenne affect the performance of binary and multi-species mixtures?

The benefits of growing Lolium perenne and Trifolium repens in mixtures have long been recognized. Increasing interest has recently been given to the productivity of multi-species mixtures including forbs. Little is known of whether genetic variation within forage species affects competition and complementarity among species in mixed stands and therewith overall sward performance. An experiment was performed with four varieties of L. perenne grown either in monoculture with nitrogen fertilization (200 kg ha-1 a-1) or in unfertilized binary (with T. repens) and multi-species mixtures (including Plantago lanceolata L. and Taraxacum officinale Web.). The L. perenne varieties differed in time of heading (early, late) and growth habit (prostrate, erect). Aboveground herbage was cut four times a year over four years. The results showed that the unfertilized multi-species mixture had the same total yield as the fertilized L. perenne monoculture. The erect form of L. perenne showed a significantly higher yield than the prostrate one, both in L. perenne monoculture and in mixture with T. repens. In the multi-species mixture the L. perenne variety had no effect on the total dry matter yield.