2009, Volume 17, Paper 7
ISSN: 1883-5675

Economics of soil management in pasture systems for sheep enterprises in the Central West Catchment of NSW

Terence C. Farrell

Abstract

In this research Grassgro® was used to compare the optimum sheep stocking rates for gross margins against the optimum stocking rates for best practice soil management for five regions in the Central West of NSW.
Five best practice management scenarios were used to evaluate the impacts of changes to pasture and soil characteristics. Results show that maintaining legumes in pastures up to the 30 per cent level would have had the greatest impact on the enterprise gross margins relative to other management changes. The next largest benefit would have been to increase soil fertility by 10 per cent as it would increase the gross margin by $17/ha at Trangie and $87/ha at Mudgee.
The optimal stocking rates according to the gross margins were 12 hd/ha for Bathurst, 8 hd/ha for Mudgee, 5 hd/ha for Dubbo and Peak Hill, and 4 hd/ha for Trangie. Minimum total herbage mass estimates indicate that there would have been insufficient ground cover for Peak Hill and Trangie at these stocking rates to minimise soil erosion. Stocking rates in these two regions would therefore need to decrease to 4 and 3 hd/ha respectively which is a reduction of 1 hd/ha in each region.