The researchers studied how different combinations of orchard grass, perennial ryegrass, and white clover affect the amount of plant material produced. They found that mixtures of these plants produced more herbage than just orchard grass alone. The best combinations were 40% orchard grass, 20% perennial ryegrass, and 40% white clover, as well as 20% orchard grass, 70% perennial ryegrass, and 10% white clover. These mixtures produced about 61% more plant material than orchard grass alone. In summer, orchard grass was most abundant, while white clover dominated in winter. Overall, combining grasses and legumes resulted in higher plant material yield compared to just growing orchard grass.