Hard-seeded annual pasture legume phases are a profitable and low risk option in mixed farming regions with low to medium rainfall

CONTEXT

Diversified cropping rotations mitigate key challenges associated with continuous or mono-cropping, including soil fertility depletion, increased pest pressure, and reduced economic resilience due to limited diversification opportunities. However, an effective rotation sequence depends on a mix of agronomic and economic factors.

OBJECTIVE

This study aimed to assess the profitability and risk levels associated with rotations integrating non-traditional hard-seeded annual pasture legumes (NHL) in the mixed farming zone of southern Australia.

METHODS

Utilizing the Land Use Sequence Optimizer (LUSO), a study was conducted over a 30-year period (1991–2020) across three locations to compare the profit and conditional value at risk (CvaR) of rotations comparing two levels of biotic stress (high or low).

RESULTS AND CONCLUSIONS

Rotations including NHL pasture were more profitable and exhibited lower risk compared to traditional improved annual pasture-legumes (TIL) or continuous cropping. These findings were consistent across various climate conditions. However, at one location (Condobolin), continuous cropping slightly outperformed the NHL rotation sequence in terms of both profit and lower risk. This was attributed to higher rainfall and temperature, where extended spring rainfall boosted canola and wheat yields. Despite greater fluctuations, overall moisture and warmth favoured continuous cropping. In contrast, at the other locations (Corrigin and Lameroo), NHL rotations were more profitable and less risky than continuous cropping.

SIGNIFICANCE

Rotations incorporating NHL pastures consistently showed resilience in locations prone to high biotic stress across all three sites. The inclusion of NHL pasture phases in mixed farming rotations improves profit and reduces risk, particularly in drier, variable regions, by withstanding dry periods and enhancing soil moisture. This is particularly beneficial in areas with variable rain-fed production, such as southern Australia's low- to medium rainfall regions. These findings highlight the ecological and economic advantages of incorporating NHL into rotations, contributing to contributing to more diversified and resilient farming systems.