ESTABLISHMENT OF LEGUMES AND GRASSES OVERDRILLED INTO HIERACIUM-INFESTED MONTANE TUSSOCK GRASSLANDS

The establishment of lotus (Lotus corniculatus), alsike clover (Trifol ium hybridum), cocksfoot (Dactylis glomerata), and mountain brome (Bro mus marginatus) were compared following overdrilling by an experimenta l strip seeder and a conventional triple disc drill in the presence an d absence of paraquat herbicide. Drilling was carried out in late Augu st or in late January at two sites on dry, undeveloped soils in the Ma ckenzie Basin, New Zealand. With August sowing, the number of lotus, c ocksfoot, and brome, but not alsike seedlings at the end of the first growing season, were higher with the strip seeder drill than with the triple disc drill. With January sowing, lotus, alsike, and cocksfoot s eedling numbers were higher with the strip seeder drill. Numbers decli ned over the following four years but the advantage of the strip seede r drill remained. Improved seedling nodulation, root development, root length, and shoot length were recorded with the strip seeder drill. D rill effects on legume herbage accumulation in Years 2-4 were not cons istent. There were no significant herbicide effects on seedling establ ishment in the first growing season but:herbicide increased legume her bage accumulation in Years 2-4, particularly with the triple disc dril l. The higher seedling establishment and enhanced early seedling growt h indicate the potential of the strip seeder drill technology particul arly for establishing species with low seedling vigour.