Evaluation of pasture legumes sown into a prepared seedbed at Tamworth, New South Wales. 1. Dry matter yield

Abstract

The potential dry matter production in autumn, winter, and spring of 15 annual and 7 perennial pasture legumes was assessed in ungrazed plots at Tamworth on the Northern Slopes of New South Wales. Seed was sown into a prepared seedbed, and dry matter yield was estimated on 24 occasions from August 1983 to November 1987. The presence of green material at each sampling time. and the actual and total dry matters, were examined. Among the annual legumes, the highest proportion of plots presenting dry matter at all sampling times, and the highest total yields, were found for Trifolium hirtum cv. Hykon (rose clover), T. subterraneum var. subterraneum cvv. Seaton Park and Woogenellup, T. subterraneum var. brachycalycinum cv. Clare (subterranean clovers), and Medicago aculeata (CPI No. 19416). The highest proportion of bare plots and the lowest dry matter yields were found for local ecotypes of the naturalised legumes T. glomeratum, M. minima and M. polymorpha, Astragalus hamosus cv. Ioman (milk vetch), and T. subterraneum var. subterraneum cv. Nungarin. After October (day 300) in 1983-87 the proportions of plots with >10 kg/ha of dry matter present as green material were Clare 85%; Hykon 78%; Woogenellup 74%; M. aculeata, Seaton Park, and Vicia villosa var. dasycalpa cv. Namoi (woolly pod vetch) 67%; M. scutellata cv. Sava (snail medic) 56%; and M. truncatula cv. Sephi (barrel medic) 52%. Total annual yields of Nungarin were often lower than those of the other subterranean clovers, with Clare having the highest yield in each year. Cumulative yields of Namoi declined markedly after 1985, while those of T. lairtum cv. Hykon increased. Little or no linear relationship was found between maturity grading and the relative yield of the annual legumes, although 4 of the 6 highest yielding legumes were late maturing. Among the perennials, yields of M. sativa cv. Pioneer 581 (lucerne) were above average in 1984-87. Lucerne cv. Pioneer 581 produced more dry matter over 5 years than Onobrychis viciifolia cv. Eski (sainfoin), but about the same amount as O. viciifolia cvv. Othello and Remont. Sainfoin production was high in the first 2 years of the experiment, but lower towards the end. The poor performance of T. repens cvv. Haifa and Huia (white clover) was attributed to high temperatures and low effective rainfall in summer. From these data, 5 annuals (Seaton Park, Woogenellup, Clare, Hykon, and M. aculeata) and lucerne show the most potential for sowing as ley pasture in the low elevation, summer rainfall environments of the Northern Slopes of New South Wales.