Tuesday, November 14, 2006 - 2:00 PM

Factors Impacting Pasture Growth Rate in Subterranean Clover-based Pastures in Southwestern Australia.

Timothy Scanlon, Len Wade, and Megan Ryan. The Univ of Western Australia, Plant Biology, 35 Stirling Hwy, Nedlands, 6009, Australia

Subterranean clover-based pastures are believed to have declined in productivity and persistence over the past thirty years in the southern areas of Australia. This pasture decline has significantly affected the carrying capacity of sheep in areas of the south-west of Western Australia, and thus, animal production for wool and meat has also declined. The basis of this pasture decline is not yet clear. Field and farmer surveys were used as basis for identifying patterns in pasture composition and performance, and their associations with climatic, edaphic, abiotic, biotic and managerial factors. The overall objective was to identify targeted environments with related constraints, examine their characteristics using a multivariate approach, and consider strategies that may be suitable for their alleviation. From a field survey of 96 sites in the south west of Western Australia, pasture growth rate data were compared with environmental and nutritional factors to measure impacts on pasture productivity. By understanding pasture growth and related nutritional and compositional factors, this study aims to understand the basis of pasture decline and the strategies that may be suitable for its alleviation in targeted situations. Patterns of pasture growth rates are presented.