Lucerne for high quality summer feed in North Island hill country

Abstract

It is common to have a shortage of high quality summer feed on hill country farms in New Zealand, due to a deterioration of pasture growth during the drier months. Lucerne produces high quality feed during summer on lowland fields; however, its potential in hill country is unknown. This study measured the persistence of lucerne and evaluated its seasonal production relative to pasture. These results were then modelled for a typical sheep and beef farm to assess the potential benefits of including lucerne on the farm. Monthly growth rates of lucerne (six cultivars) and pasture were measured pregrazing, and lucerne viability was assessed at the end of the five-year study. Lucerne was successfully established and maintained on hill country for five years. On average, the total annual production of lucerne and pasture were similar, with only the highest yielding cultivar 'Rere' consistently outproducing pasture on an annual basis. Lower spring production of lucerne was compensated for by higher summer growth rates of 62 kg DM/ha/day, compared with 34 kg DM/ha/day for pasture. The extra summer feed from lucerne enabled a model farm that included 12.5% lucerne to carry more animals and produce lambs of heavier slaughter weight than on a pasture only basis. This gave a predicted increase in the gross margin of 3%. The impact of lucerne on other farms must be modelled individually to establish the best system to utilise the additional high quality summer feed. Key words: lucerne, modelling, quality summer feed