Pasture legumes for the drought-prone, outwash soils of the southern Mackenzie Basin.

摘要

The persistence of lucerne (Medicago sativa), red clover (Trifolium pratense), birdsfoot trefoil (4 genotypes of Lotus corniculatus) and perennial lupin (Lupinus polyphyllus), overdrilled with and without each of 7 companion grasses, was compared ata site representative of dry, acidic, outwash soils in the southern Mackenzie Basin, South Island. Plant populations were monitored for 9 years and legume seedling regeneration and stand recruitment were examined over three consecutive years under grazing by sheep and cattle. Perennial lupin was the best adapted legume species. Stand density increased by resowing. In contrast, few seedlings of birdsfoot trefoil developed as a result of resowing, and survival of birdsfoot trefoil was generally restricted to the more favourable areas of the mosaic of soil. Red clover did not persist, and the few plants of lucerne that survived lacked vigour. Tall oat grass [Arrhenatherum elatius] and cocksfoot [Dactylis glomerata] showed good vigour and persistence across the mosaic of soil; smooth brome [Bromus inermis] performed well and spread within the more favourable areas. From these results, perennial lupin, tall oat grass and cocksfoot appear to be the best species available for the future development of sustainable pastoral systems in drought-prone outwash landscapes in the Mackenzie Basin.