Perennial ryegrass thrives on most soil types, except when under very dry conditions or infertile soils.
The species is perennial and suitable for both grazing and cutting. Perennial ryegrass has high sugar content, high digestibility and produces a high yield of good quality. Perennial ryegrass is particularly suitable for mixtures with white clover.
Diploid varieties are – compared to tetraploid – distinguished by being more fine-leaved and dense in growth. They are more resistant to damage by grazing cattle. The diploids have a higher dry-matter content.
Tetraploid varieties are typically darker and more broad-leaved, and slightly higher yielding with higher sugar content, better winter hardiness, and more open growth. DLF has developed tetraploid varieties that are as dense as most diploids, making them particularly suitable for grazing. Their seed size is larger than diploids making them ideal for inclusion in over-seeding mixtures. They produce fewer, larger tillers than diploids leading to more open swards which can give better compatibility with white clover. Their development is regarded as a major advance in grass breeding.
Diploid or tetraploid?
Recent research has shown that most tetraploids outperformed diploids for grazing utilisation. Thirty varieties of perennial ryegrass on the 2016 Irish recommended list were rotationally grazed by dairy cows. The total available herbage was measured as were the pre and post- grazing heights allowing for the grazing utilisation to be determined. This improved utilisation and hence intake will improve the yield of both milk and meat.
An increased amount of grass in the cow´s feed ratio will