Farm Table says:
What is the problem?
Summer active, tropical perennial grasses have shown potential in southern Australia but the establishment is risky as it requires a combination of warm but moist soils for successful pasture establishment. The aim of this study was to define optimal sowing windows for the low rainfall zone (250-400 mm) of southern Australia.
What did the research involve?
By interrogating historical climatic data (SILO) using two sets of rules that identified conditions for potentially successful seed germination and pasture establishment sowing windows were identified.
What were the key findings?
In general, early October presents the most opportunities to successfully establish tropical grasses. However, the duration of the sowing window and number of opportunities in any given year varied greatly across the region. The data is helpful for planning purposes and assessing potential suitability of different zones as field experimentation has shown that once established, perennial tropical pastures can grow well and persist in a low rainfall environment.
Field trials in low rainfall locations in southern Australia and grower experience in low-medium rainfall regions of Western Australia have demonstrated the potential for tropical grasses to establish, persist and provide valuable summer growth and groundcover. However limited opportunities for effective establishment continue to be a major limitation to their widespread uptake. This study used an interrogation of daily climate data to highlight why establishment poses a major limitation and risk in the low rainfall zone; but has also shown that establishment opportunities can occur, particularly in localities receiving greater than 350 mm rainfall and mostly in September and October. Growers wanting to establish tropical species will need to be prepared to take a highly opportunistic approach based on well informed and judicious decisions about current edaphic and climatic conditions, as well as those forecast for the near future.