Influence of cutting date and frequency on dry matter production and nitrogen content of autumn-sown greenfeeds

Abstract

The dry matter production of autumn-sown ‘Amuri’ oats, ‘Raven’ wheat, and ‘Grasslands Tama’ ryegrass grown to the milky-ripe stage of grain development before cutting was compared with yields from either 2 or 2–6 cuts made during growth. Nitrogen content was determined in initial-cut herbage at intervals during growth and in the 6-cut regrowth herbage. Delaying the initial cut from May or July through to December increased dry matter production. However, nitrogen content declined from about 4–5% in July–August to less than 1% in November–December. Compared with a single cut in December oat and wheat yields were steadily reduced by increasing the number from 2 to 5 or 6 and Tama yields were similarly reduced up to 4 cuts. The pattern was similar to oats grazed by sheep. Total regrowth yields of Tama ryegrass exceeded those of oats which exceeded those of wheat. Oats and wheat failed to regrow when the initial cut was made after September when sown in March, and after October when sown in April. Tama failed to regrow if the initial cut was made after October. Nitrogen content of regrowth herbage was high (c. 3.5%) from August to November but decreased to about 2.3% in December.