Effects of Concord ryegrass and nitrogen fertiliser on feed production on a seasonal dairy farm

Abstract

The seasonal production of autumn-sown Concord Italian ryegrass was compared with that of an existing perennial ryegrass pasture. Concord (10 kg/ha) was direct-drilled into large plots previously. sprayed with glyphosate or was undersown into the existing pasture. Nitrogen fertiliser (25 kg N/ha) was applied to half the area of each plot on 3 occasions during June and July. The major objective of the experiment was to examine the effects on pasture production in late winter-early spring (early lactation) when cows are often underfed. During late winter-early spring, direct-drilled and undersown plots accumulated 44 and 20% more dry matter (DM), respectively, than did the existing pasture (2.5 t DM/ha). Addition of N increased overall accumulation during early lactation by 18%. The direct influence of Concord on pasture accumulation was restricted to winter/spring, as was the pasture response to N. Argentine stem weevil populations were low and were not affected by winter applications of N. This work suggests Italian ryegrasses, like Concord, can be used to boost feed production during early lactation on dairy farms, and that winter N applications can be used to enhance their contributions. Further farmlet work is required to determine the milk production responses possible from the use of Italian ryegrasses. Keywords Lolium multifloru-m, ltalian ryegrass, direct drilling, seasonal herbage accumulation, early lactation period, pasture botanical composition, tiller density, major element composition, Argentine stem weevil populations