Salinity response of cultivars of buffel grass (

Buffel grass cultivars were grown in solution culture at levels of 0.5, 40, 80, and 160 m. equiv. NaCl/l. Yields did not differ between cultivars at the highest level of NaCl, and the more productive cultivars under low salinity conditions, Tarewinnabar, Biloela, and American, suffered greatest potential yield reduction and accumulated highest sodium concentrations. Biloela cultivar maintained relatively high yields up to the 80 m. equiv. NaCl/l level

Growth responses of Desmanthus virgatus to inoculation with Rhizobium strain cb3126. II. A field trial at 4 sites in south-east Queensland

Growth of Desmanthus virgatus cvv. Marc, Bayamo and Uman, inoculated with Rhizobium strain CB3126, was compared with that of uninoculated and inoculated + nitrogen-fertilised plants at 4 sites in south-east Queensland over a 3-year period. Supplementary irrigation was used to ensure prompt establishment. The proportion of nodules due to the inoculum strain was determined using serological methods and the proportion of total plant nitrogen arising from biological fixation in the second and third years was estimated using the natural abundance method. Top growth was increased significantly by inoculation at 3 sites in the first year and at 1 site in the second year. Growth increases relative to uninoculated plants varied from 34–313% and appeared to depend on the prevalence of indigenous strains and soil nitrogen level. The inoculum accounted for few ( 94%) of the nodules formed in soils in which nodulation of uninoculated plants was high, medium and low, respectively. The proportion of total nitrogen due to biological nitrogen fixation in the second and third years ranged from 0% in a highly fertile soil to 38–98% in 3 soils of low-moderate fertility. The ability of strain CB3126 to increase growth of desmanthus in some soils was confirmed in these field trials. Inoculation of desmanthus seed with an effective strain of Rhizobium such as CB3126 is recommended

Sward evaluation of eleven 'Stylosanthes seabrana' accessions and S. scabra cv. Seca at five subtropical sites

Sown pasture development in the light-textured soils of the seasonally dry tropics and subtropics is based mainly on Stylosanthes species. S. scabra cv. Seca, the cultivar most widely sown, has poor long-term persistence and yield in lower-rainfall subtropical environments experiencing frosts and drought, particularly on clay soils. This study has identified accessions of "Stylosanthes seabrana" which perform well on clay soils in the subtropics, greatly extending the contribution that Stylosanthes species can make to beef production in northern Australia. Although there was abnormally low rainfall during the first 2 years of the experiment, the stylos established and survived in all environments. Most "Stylosanthes seabrana" accessions were consistently superior to Seca in seedling and perennial plant density and yield at most sites, particularly in the third year of the experiment. Seca performed poorly in all attributes in all years with the lowest rank over all years indicating its lack of adaptation. The accessions 92838B and 110361 were selected and released as cultivars Primar and Unica, respectively, in 1996. Primar appears better adapted to the more southerly subtropical sites with early frosts and a short growing season. Unica appears superior to Primar in central Queensland which normally has a longer summer growing season

Options analysis improves beef enterprise performance, profitability and technology adoption in central Queensland

Successful technology transfer and the implementation of improved practices for livestock breeding, pasture development and livestock marketing have resulted from whole-of-enterprise modelling and financial analysis. Beef producers are able to identify opportunities for improving enterprise profitability, evaluate financial outcomes of options and confidently implement practices once they have had a learning experience which demonstrates, by simulation, the profitability and affordability of the innovation. Herd models are used to compute performance indicators/ benchmarks for comparing "with and without change" options while action learning groups identify opportunities and cash flow budgets determine the financial feasibility of options. A number of case studies are presented