The effect of cutting frequency and applied nitrogen on production and digestibility of perennial ryegrass

Grass swards were cut at intervals of 2, 3, 4, 5, 6 and 8 weeks and received 336 or 673 kg ha −1 nitrogen the higher level being applied as a single or as split dressings. Reducing cutting interval from 8 to 2 weeks reduced mean DM yield by 37% from 14·2 to 9·0 t ha −1 and digestible DM yield by 24% from 9·4 to 7·2 t ha −1 . The response to the extra N at the highest level of application was greatest under the most frequent cutting regimes. Application of N did not affect the digestibility of DM. Results are discussed in relation to the comparative effects of frequency of cutting at different seasons of the year and at different levels of N.