Crop nutrition can affect crop responses to frost, so crop nutrition strategies need to be different for frost prone paddocks.
Identify frost prone areas on farms, and aim to maximise profit rather than yield in those areas.
Tissue test to understand copper levels across the farm and don’t run with deficient levels of Copper – regardless of frost risk. Additional copper above sufficiency is not likely to provide any frost protection.
Deficient crops have weaker cell walls and higher screenings at processing. Make sure soil and plant levels are adequate for crop development, but luxury levels don’t seem to give additional tolerance to frost.
High nitrogen develops a dense canopy, this can intensify frost effects at the height of grain heads, exacerbating crop damage. Don’t aim N nutrition for high yield targets on frost prone paddocks, a more conservative yield target will tend to give better average returns.
Garren Knell works with GRDC’s National Frost Initiative and won the ‘Seed of Light’ award for the Western region in 2016.
Richard Bell, UWA, Rob Norton, IPNI