CHANGES IN THE PERENNIAL RYEGRASS COMPONENT OF GRAZED PASTURES

The contribution of perennial ryegrass to pasture production is dependent on the stage of development of the pasture, climate and pasture management. Although variability in the percentage of ryegrass in improved pastures is less than in developing pastures, changes in the ryegrass component in response to different managemcnts can be marked. Tiller counts demonstrated a lower population of ryegrass tillers under rotational grazing by cattle than under sheep. This was increased by changing either from cattle to sheep grazing or by hard set stocking with sheep during spring. Grazing to 3 cm produced more dense ryegrass pasture than grazing to 6 cm. Severity of grazing appeared to be particularly important in dry conditions when grazing below 3 cm is likely to reduce tiller density. A range of management options is therefore available to encourage the perennial ryegrass component, and thus total dry matter production, of improved pasture.