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Abstract
In dryland agricultural systems, efficient farm management requires a degree of flexibility
according to variations in climate from year to year. Tactical adjustments to the mix of
farm enterprises can capitalize on good growing conditions and minimise losses under poor
growing conditions. In this paper, a discrete stochastic programming model of dryland
wheat-sheep farms in Western Australia is used to identify optimal tactical adjustments to
climate and to calculate the value of these tactical adjustments. The model, MUDAS,
includes nine discrete season types with a wide range of options for tactical adjustments in
each. In the standard model, optimal tactical responses increase expected net cash surplus
by approximately 22% relative to a fixed or inflexible strategy. In most season types, changes
to the long term farm strategy are made on less than 10% of the farm area, although in
some seasons over 25% of the farm can require adjustments to the enterprise selected. The
benefits of flexibility are not evenly distributed across different season types but occur
predominantly in the best and worst seasons. The magnitude of benefits is affected
differently by different commodity prices. Benefits of flexibility are due to capitalizing on
knowledge about the greater volatility of profits from cropping than from livestock production.
Deterministic models and even stochastic models which don't include activities for
tactical adjustments miss this key feature of the system.