Establishment and survival of lucerne in a semi-arid environment.

Abstract

Dry matter production and plant density were measured after seeding lucerne: (Medicago rarii'a) into grassland at two sites in New South Wales having inearl annual rainfalls of 292 and 425 mm. Various methods of minimal tillage establishment were used. Sod-seeding failed to produce a satisfactory stand at either site, even where herbicide had been applied. Survival was best when lucerne was sown in furrows 15 cm wide, the lucerne density after five years being 8 plants ~n'~, or 80,000 plants ha-'. This treat- ment was also superior in dry matter production to the use of furrows of 5 and 10 an width, or to seeding after a single cultivation. The effect on production of a herbicide applied at sowing decreased with increasing width of furrow. The results of this study could also be relevant to the establishment of other species under rangeland conditions.