An annual relay intercropping of grasses and legumes (LGI) (50:50) was compared with the sole crops, respectively, to determine the effect of the mixtures on the yield and quality of them as fodder in the Mediterranean region. The treatments were sole Rye (; G1), Ryegrass ( G2), Faba bean ( L.; L1), Berssem ( L.; L2), inoculated Clover ( L.; L3), and all the combinations of grasses and legumes. The experiment used a randomized block design with three blocks. ANOVA showed significant effects of intercropping on the biomass yield (BY) and the forage quality. Monocrops L2 and L3 showed better fodder quality than LGI and L1. The relative land-use efficiency (RLI) was higher for four out of six intercrops, while G2L1 and G2L3 had an RLI < 1, indicating lower efficiency than their monocrops. The Aggressivity Index (AG) showed that L1 was competitive against the grasses. The Relative Yield Maximization (RYM) demonstrated that intercropping significantly improved the biomass yield. The competition indices revealed that G1 with legumes had the highest efficiency and economic viability (ELER > 1), while the G2 combinations were less profitable. The study highlights the importance of selecting species based on soil fertility and climatic conditions to optimize intercropping outcomes.