1. Western Australian Dep. of Agriculture, Div. of Resource Management; Geraldton WA 6530 Australia
2. CSIRO, Div. of soils; GPO 639 ACT 2601 Canberra City Australia
3. Victorian Dep. of Agriculture and Rural Affairs; Animal and Irrigated Pastures Research Inst.; Kyabram RMB 3010 Victoria 3620 Australia