Farm Table says:
Best management practises for low rainfall environments
What is the problem?
Canola is a minor crop in many low rainfall areas, particularly when compared to higher rainfall zones.
This research looks to increase growers’ confidence in canola by combining existing knowledge with carefully targeted field research and modeling to produce the best management package for low rainfall environments of eastern Australia.
What did the research involve?
- sowing Time – two trials were conducted to determine the optimum sowing time for the region and to assess the degree of sowing date by maturity interaction, to help determine which maturity class is the most appropriate
- the 2002 season was one of the driest on record in the central west and the 2003 season was also well below average, requiring supplementary irrigation to achieve results. In each year and for all varieties, yield was highest for the earliest sowing date and declined with each delay in sowing
- these trials also examined the interaction between sowing time and variety to help growers decide on the most appropriate variety maturity group. In 2003, the early maturing AG-Outback and Hyola 60 gave the highest yields from late (June ) sowing but these were still below 0.4t/ha
- detailed soil moisture measurements were taken at about three-week intervals under a number of varieties at each sowing time to quantify water use and the effective root zone
- importance of stored soil moisture – the second area requiring field work was quantifying the value of stored water
- crop modelling – simulation modeling can be valuable in placing research outcomes in a long-term context and in examining variability. This can be done using a validated crop model and long-term weather records
What were the key findings?
- some increase in the area sown to canola is expected, but adherence to the guidelines will result in a significant number of years in which canola will not be sown in some areas
- growers will be able to benefit from canola as a cash crop in the appropriate years and from the rotational benefits of canola to subsequent cereal crops, but their farming systems will need to be flexible to respond to the seasonal conditions
- hile the performance of the two Indian mustard varieties trialed in 2003 was not exceptional, there was some indication that they may be competitive with canola from May sowings
These guidelines will greatly increase the reliability and profitability of canola production in low rainfall areas. However, it will also result in a significant number of years in which canola will not be sown in some areas.