The influence of fertiliser and ground cover on growth and survival of tussock species on mountain subsoils.

Seedlings of five native tussock species grown in the glasshouse on mountain subsoil showed outstanding responses to nitrogen and phosphorus fertiliser in combination. The most vigorous species was silver tussock but this produced less dry matter than an introduced grass, Yorkshire fog, grown on the same soil. Tussocks in general responded positively to applications of magnesium and potassium but growth was depressed by lime.
In field sowings at two sites under different vegetative covers tussock seedling survivals over a five summer period were very low. Improved survival in early years through protection by cover species appeared to be offset in later years by competition for nutrients from the same species. Best survival rates were shown by blue tussock and silver tussock.