Sediment yields and soil loss rates from native forest, pasture and cultivated land in the Bathurst area, New South Wales

Summary Sedimentation surveys of small dams in granite catchments in the Bathurst area of New South Wales (NSW) demonstrate that land use is the dominant factor determining soil loss rates and sediment yields. We found that cultivated catchments produced, on average, 3.1 t ha−1y−1 whereas grazed pasture and forest/woodland catchments exported only 2.2 and 0.8 t ha−1y−1, respectively. The yields for cultivated and grazed catchments are high by Australian standards. Dam sediments were enriched in clay and organic matter in comparison to catchment topsoils. The dams were deliberately selected so that gully and bank erosion were not active geomorphic processes in the catchments and so the measured sediment yields could be validly compared to soil loss rates predicted by various versions of the Universal Soil Loss Equation. The Modified Universal Soil Loss Equation, Soiloss and Revised Universal Soil Loss Equation did not closely predict the measured sediment yields, as we have found ensewhere in NSW. Although Soiloss is the only empirical equation to use Australian data, it is not as accurate in the Bathurst area as for areas near Sydney. Further research is needed to test and develop soil loss prediction equations under Australian conditions.