An overview of dryland legume research in New Zealand

With limited funds, and the relatively low importance of dryland pastures in New Zealand, research has been targeted at the species most likely to induce transformational change on-farm. Lucerne research into biophysical influences on plant growth and development has added flexibility to spring grazing management. Coupled with additional agronomic research and extension, farmers now have the confidence to use lucerne as a direct feed source for sheep, beef and deer. Research on Caucasian clover seedling development identified the long duration to secondary leaf production as the physiological basis for slow clover establishment in mixed swards. Despite agronomic strategies to overcome this, its use is now limited by commercial constraints. A 10-year 'MaxClover' grazing experiment at Lincoln University demonstrated the superiority of subterranean clover with cocksfoot over perennial ryegrass and white clover for pasture persistence, quality and animal performance. Pastures with high legume content had higher water-use efficiency and produced greater animal and pasture production. Balansa and gland clovers both show a strong influence of photoperiod on time of flowering, which suggests they may be suitable for oversowing into areas of winter wet and summer dry hill and high country. Further research into their ecological niche and ability to regenerate each autumn is required. For all legumes, the role of inoculation requires further research with recent results suggesting indigenous, rather than commercially introduced, bacterial populations are dominant in root nodules. Uptake of dryland pasture species for on-farm use has only been successful when research, extension and agribusiness interests have been aligned.