COMPARISON OF SECALE WITH OTHER PERENNIAL GRASSES UNDER GRAZING AT A COOL SITE IN THE HIGH RAINFALL ZONE OF NEW-SOUTH-WALES

In 2 field experiments on the southern highlands of New South Wales, t he short-lived perennial grass secale (Secale montanum Guss. cv. Black Mountain) was grazed by Merino wether weaners at stocking rates of 10 -17 animals/ha to test the suggestion that persistence might be enhanc ed by occasional deferment of grazing to encourage seedling germinatio n. In the first of these experiments (experiment 1), designed to compa re secale and phalaris, when accompanied by white and subterranean clo vers, growth and survival of both grasses was poor, despite the applic ation of >600 kg/ha superphosphate and the experiment was abandoned af ter 2 years. A subsequent pot trial (experiment 2) with secale grown i n soil from the experimental site, where the fertiliser had been appli ed, showed a large growth response to additional phosphorus. Because i nadequate soil fertility may have been the cause of poor grass persist ence in experiment 1, a second field experiment (experiment 3) was est ablished on the same site to compare secale, perennial ryegrass and co cksfoot, each accompanied by white and subterranean clovers and with t he application of a further 850 kg/ha superphosphate over 3 years. Ini tial growth of all the grasses was good and animal production on the s ecale and ryegrass plots was high (up to 100 kg/ha greasy wool and 300 kg/ha Liveweight gain). Secale failed to survive more than 3 years, d espite deferment of grazing and it may be that persistence depends mor e on the reliability of autumn rainfall. However, mean weight gain fro m the clovers and volunteer grasses on the secale plots in the fourth year was as high as from the ryegrass plots and double that from the c ocksfoot plots, which became increasingly cocksfoot-dominant. While th e results indicate a need for more work on the fertiliser requirements of perennial grasses on these soils, they also raise questions about whether these grasses benefit animal production sufficiently to justif y the cost of establishing them.