Effect of seed component ratios and cutting regime on the performances of annual ryegrass and burr medic mixtures

A research was carried out in Sardinia (Italy) to identify the best combination and management in binary mixtures of Lolium rigidum Gaudin Nurra (L) and Medicago polymorpha L. Anglona (P) new released varieties of both species. Two pure stands (L100P0 and L0P100) and three mixtures (L75P25, L50P50 and L25P75) were compared under two cutting regimes; a commercial mixture was also included in the experiment as test. Forage yield and quality, biological efficiency, interspecific interference and competitive ability of both species were assessed. Total dry matter yield ranged from 2.2 to 5.6 t ha-1 (two-cuttings) and from 2.3 to 4.9 t ha-1 in commercial mixture and L25P75 (three-cuttings). The association grass-legume showed positive effects on the control of unsown species. Crude protein yield, neutral detergent fibre, acid detergent fibre and acid detergent lignin concentration significantly varied between mixtures. The highest protein yield was obtained in the L25P75 mixture, reaching 1308 kg ha-1 in two-cuttings, as well as the best combination for quality and yield that maximised the synergic interaction effects between species. Key words: Annual self-reseeding species, forage quality, grass legume competition, mixtures.