Growth of 15 legumes was monitored for 3 years on 3 Otago upland soils with 11, 45, or 70 µg g -1 extractable soil aluminium (Al). Lotus pedunculatus and L. corniculatus produced the greatest dry matter over the 3 years, with L. pedunculatus producing superior yields at intermediate and high soil Al sites. Within white clover, types selected for Al tolerance produced similar yields to types selected for Al susceptibility, and four commercial white clover cultivars and an alsike clover (Trifolium hybidum). Caucasian clover (T. ambiguum) spread by rhizomes at the high Al site, but neither Lotus species spread from the planted row. Some white clovers showed limited spread. It is concluded that optimising performance of Lotus and Caucasian clover on these soils will be a more productive strategy than breeding for Al-tolerance in white clover. A00037

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The performance of 55 Lotus pedunculatus Cav. and 33 Trifolium repens L lines of diverse type and origin was assessed on acid, infertile soils on the East Otago Plateau at 3 sites representing an altitudinal sequence of increasing severity of climate. Among the L pedunculatus lines, a diploid NZ selection 04701 showed the best combination of attributes with high herbage yields, moderate rhizome spread at the highest sites and considerable tolerance to out-of-season frosting. G4701, its tetraploid equivalent G4702 and a selection from within the cultivar 'Grasslands Maku' for rapid germination at low temperatures, produced the highest yields averaged over the 3 sites in the altiludinal sequence. The use of these lines is likely to enhance the role of lotus in tussock grassland pasture systems. Within white clover, a hybrid line C5413. which has been.included in the pre-release Southern white clover cultivar G26. performed well, indicating that it has wide adaptability for both fertile lowland and low-fertility hill and high country situations on the southern South Island. The Southland Selection C5844, which is derived from Southland ecotypes, had the best combination of attributes for the East Otago Plateau. This selection merits serious consideration for release as a 'Tahora-like' cultivar for moist, infertile hill and high country in the southern South Island. Keywords: Trifolium repens, Lotus pedunculatus. evaluation, herbage yield, spread, dominance, frost damage, South Island.

Birdsfoot trefoil (Lotus comiculatus L.) is a species with considerable potential for hill and high country of the South Island; however, difficulties in maintaining satisfactory stands due to problems with persistence have been reported. Plant recruitment through natural reseeding is considered a necessary tool for the maintenance and improvement of birdsfoot trefoil stands in the USA, but research which investigates the role of soil seedbanks, seedling recruitment and stand management for improving the persistence of birdsfoot trefoil in the drier hill and high country of the South Island of New Zealand is limited. Two field experiments in the dry hill and high country of Otago monitored changes in stand populations and seedling emergence of birdsfoot trefoil under differing grazing management. At Ardlui Station on the Coastal Otago Plateau, seedling emergence was greatest in autumn rather than spring after spelling over the flowering period. Despite considerable numbers of autumn seedlings (128 seedlings/m2), less than 1 seedling/m2 survived to contribute to the stand after 12 months. Plant populations did,however increase in 199l/92 following adequate rainfall in the previous autumn. Spring emerged seedlings did not survive through summer. At Omarama Station in the southern Mackenzie Basin, plant populations of birdsfoot trefoil continued to decline despite the presence of seedlings in spring and autumn. Results imply that natural reseeding cannot be relied upon to improve birdsfoot trefoil plant populations unless favourable climatic conditions prevail during spring or autumn. Keywords: establishment, Lotus corniculatus, management, natural reseeding, persistence, seedling recruitment, soil seedbanks, survival

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