Effects of cutting regime on pasture production

Abstract

Pasture production was measured at Invermay over 3 years in an experiment with 6 different cutting frequencies (which included cutting decisions based on either height or time) and 2 cutting severities.Infrequent cutting outyielded frequent cutting, especially in the spring and early summer. During the dry summer-autumn period a cutting frequency of between 4 and 6 weeks appeared optimal except in a very dry year. A cutting decision based on mean pasture height was better related to the pattern of pasture growth than a decision involving cutting at regular intervals. Cutting to 3 em consistently outyielded treatments cut to 6 cm.

Pasture response to soil phosphorus levels measured under mowing and dairy grazing

“…Because ryegrass was the dominant pasture species present in our trial, it would be expected to strongly influence pasture production. Reid (1966) and Boswell (1977) reported an increase in ryegrass production from mowing down to a height of 30 mm compared with mowing to 60 mm, so once again the difference in severity of grazing and cutting does not explain the reported difference in ryegrass content from our study.…”

“…In our study, grazing and mowing frequency was similar at 4-6 weeks or when pasture mass reached at least 2 t DM ha-1. Mowing at a similar pasture height (30 mm) as in our trial has been reported to increase pasture production compared with mowing to a height of about 60 mm (Reid 1966;Boswell 1977), which is approximately equivalent to the postgrazing pasture mass for most of the year. Therefore, it appears that neither differences in frequency or severity of grazing or mowing can explain the difference in pasture production.…”

“…This increase in production could possibly be attributed to the pasture in the paddocks being grazed less frequently than the plots were mown (Boswell 1977;Williams & Morton 1987), or the pasture in the paddocks being grazed at a greater height than the plots were mown. In our study, grazing and mowing frequency was similar at 4-6 weeks or when pasture mass reached at least 2 t DM ha-1.…”

Effects of mowing interval, return of clippings, and potassium fertiliser on production and botanical composition of pasture in a mowing trial

“…Increasing the mowing interval from 3 weeks to 6 weeks allowed the pasture to grow to a greater height and resulted in increased annual pasture growth. Similar effects of frequency of cutting on production have been recorded in other small plot mowing trials by Hamblyn (1954), Lynch & Mountier (1954), Reid (1966), andBoswell (1977). It has also been reported in grazing trials (Brougham 1959).…”

“…To overcome this problem it might have been better to mow on a height basis rather than a time basis. Boswell (1977) compared cutting frequencies based on time with those on height and concluded that height was a better parameter to maximise yield.…”