It is recognised that pasture utilisation is not necessarily driven by economics and that other drivers are likely to be important to decisions about stocking rate and pasture utilisation , for example , maintaining cash flow to service debt is a rational basis for running much higher utilisation rates over the short term . The results are indicative and provide a useful comparison between land types in the BBB catchment .
The Goldfields land type results ( Figure 24 , Figure 25 and Table 6 ) show that :
• The economically optimal pasture utilisation is between 15 % and 20 % TSDM for B and C starting land conditions , and 30 % TSDM for A start land condition ( Figure 24 and Figure 25 ).
• Land condition makes a big difference to the net present value ; at the economically optimal pasture utilisation of 30 % TSDM the “ A ” start condition net present value of $ 4,674,053 is substantially more than the “ B ” ($ 2,516,873 ) or “ C ” ($ 1,148,839 ) start conditions ( Figure 24 ).
• The net present values are lower for the tree scenario ( Figure 24 ) than the cleared scenario ( Figure 25 ) across the three starting conditions , and the tree scenario also has higher sediment exported for each start condition . This makes the cost per tonne to reduce sediment a cheaper option on scenarios with trees due to the combination of both a lower net present value and higher sediment exported . The higher sediment exported from the treed scenario is due to the higher areas of bare ground underneath trees that is more prone to erosion .
A negative cost means that no incentives are required to achieve reductions in sediment exported . Rather , funding on education and extension is required to assist producers understand that their economic position will be enhanced if they reduce their pasture utilisation , and simultaneously reduce sediment exported .
Figure 24 . Results for Goldfields land type with 0 tree basal area ( cleared ). Source : Star et al . ( 2013 ).
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