Evaluation of legumes for introduction into native grass pastures on the North-west slopes of New South Wales

摘要

A range of pasture legumes was either broadcast or drilled into native grass pastures on the North-west Slopes of New South Wales to identify legumes that would persist in that environment and improve the quality of winter pastures based on native grasses. There were 2 experiments conducted over 12 sites. In the first, sites were selected to permit identification of effects of altitude and 2 soil types on legume adaptation. In the second, the lower altitude range was extended and a wider range of soil types was sampled. Subterranean clover (Trifolium subterraneum L.) was the most persistent and productive species, with cultivar performance varying with altitude. At the lowest altitude (340 m) the early-maturing cv. Dalkeith was the most productive, and at 500-600 m there was little difference between the tested cultivars. Stand density, herbage yield, and seed yield all declined as altitude increased, but the decline was greater with earlier maturing cultivars than with the later maturing cv. Woogenellup White clover (T. repens cv. Haifa) established poorly in native grass swards, but plants that did establish persisted during favourable seasons at higher altitudes. Herbage yields of woolly pod vetch (Vicia dasycarpa cv. Namoi) and rose clover (T. hirtum cv. Hykon) occasionally exceeded yield of subterranean clover at some lower altitude sites, but those species failed to persist at other sites where grazing management may have been unsuitable. Barrel medic (Medicago truncatula) established satisfactorily but did not persist on the more acidic soils (pH <6.0). Both drilling and broadcasting establishment techniques produced satisfactory legume stands. Legume plant density was generally greater on heavier soils of basaltic origin than on lighter soils of rhyolitic origin.