Some factors affecting the establishment of four native grasses

The effects of fertilizer application, types of mulching and times of sowing on the field germination of seed of four native grasses (Themeda australis, Bothriochloa macra, Danthonia spp., and Stipa bigeniculata) are reported. Growth of these species in controlled environments was compared with that of Lolium perenne (ryegrass) at three temperature regimes and two levels of nutrition. Application of an NPK fertilizer had no effect on emergence or survival of the native grasses in the field. Mulching with paper or straw increased emergence of all four species and mulching with bitumen increased emergence from Themeda, Bothriochloa and Danthonia seed only, but decreased survival of the two latter species. In both field and controlled environments, germination and seedling growth of Themeda and Bothriochloa were best when maximum daily temperatures were greater than 30¦, whereas Danthonia and Stipa germinated and grew most satisfactorily when maximum daily temperatures were about 25¦. Growth of Stipa seedlings in a controlled environment was enhanced by a high level of nutrition but growth of the other species was not. Sowing seed in late spring and using a straw mulch should ensure satisfactory levels of establishment of native grass seedlings in the field in south-eastern Australia. Fertilizer application should not be necessary