Rick Llewellyn 1, Therese McBeath 1, Marta Monjardino, Jackie Ouzman1, Bill Davoren 1, Vadakattu
Gupta 1, Damian Mowat 1, Michael Moodie 2
1 CSIRO, 2 Mallee Sustainable Farming (MSF)
Presented at the GRDC Grower Updates, 13th August 2014, Waikerie, SA
Take home messages
– There is strong support from mallee research and economic risk analysis for the use of soil-specific N management to improve profitability and reliability of returns from fertiliser N on mallee crop paddocks.
– The highest yielding part of the paddock is not necessarily where the return on extra N fertiliser is highest – aim for where returns on each dollar of N applied are likely to be greatest.
– Applying extra N at seeding rather than at GS31 has usually been the best option.
– Shifting fertiliser inputs from heavy constrained soils to sandy topsoils can have significant profit and risk benefits over several years but nutrient reserves need to be monitored.
– The gross margins of break crops are usually riskier than for cereals but the effect of a legume-based break on cumulative wheat yield over the next couple of years has been relatively reliable.