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

Abstract

The persistence of lucerne (Medicugo sativa L.), red clover (Trifofiumpratense L.), birdsfoot trefoil (Lotus cornicufatus L.) and perennial lupin (Lupinuspolyphyks Lindley), overdrilled with and without companion grasses, was compared at a 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. Pcrcnnial lupin was the best adapted legume species. Stand density increased by re-seeding. In contrast, few seedlings of birdsfoot trefoil developed as a result of reseeding, 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 and cocksfoot showed good vigour and persistence across the mosaic of soil; smooth brome performed well and spread within the more favourable areas. From these results, _p_erennial.lupin,-tall-oat-grass-and-cocksfoot~a~~ to be the best species available for the future development of sustainable pastoral systems in drought-prone outwash landscapes in the Mackenzie Basin. Keywords: dryland, establishment, Lotus corniculatus, Lupinus po&phyflus, outwash soils, pasture legumes, persistence, seedling recruitment