Identification of superior native and introduced grasses for low-input pastures in temperate Australia

This paper is the fifth in a series describing trials evaluating native and introduced grasses at eight locations across temperate Australia. In these trials, 62 perennial grass lines were assessed for herbage production, survival and recruitment under low fertiliser conditions using spaced plants produced in glass houses and transplanted into the field. Sites were grouped into three different climatic zones: Eastern Australian permanent pasture, Eastern Australian mixed farming and Mediterranean zone. For each of these zones, superior lines were identified and their potential use in permanent pastures or mixed farming discussed. Among the C₃ grasses tested, several lines of 'Dactylis glomerata' from France on the Mediterranean coast near the Spanish border and from north-west maritime France proved to be superior lines in all zones and were better than the standard comparator cv. Currie with regard to the attributes assessed. In general, the 'D. glomerata' lines were superior to the C₃ native species except with respect to survival and recruitment. The C₄ introduced standard comparator 'Eragrostis curvula cv.' Consol was outstanding with regard to its herbage production and survival in all climatic zones, although its recruitment was generally low. Native C₄ lines of 'Themeda australis' and 'Paspalidium jubiflorum' yielded well in all climatic zones, and even produced more herbage than Consol in one zone. Survival rates of 'T. australis' and 'P. jubiflorum' were also very high but recruitment was low under the conditions of the trial. In mixed pastures C₄ grasses may reduce fluctuations in feed supply as well as increase water use. As a consequence mixtures of superior C₃ and C₄ lines identified in this study are likely to be suitable for pastures on infertile soils and in zones subjected to continuous or periodic drought. Further work on the behaviour of these superior lines under sward conditions in association with forage legumes and their responses to grazing is needed; however, for the promising native lines, sward trials are not possible until suitable technology for commercial seed production and broad acre establishment of these lines has been developed.