How important is season specific or soil specific wheat agronomy in southern Australia?

Abstract

Historical sequences of wheat yield for locally relevant soil types, cultivars and agronomy for locations spanning southern Australia were obtained from the National WhopperCropper database. At each location, wheat performance was simulated in response to a factorial combination of agronomic treatments, including wheat variety, time of sowing and nitrogen management. Sources of variation, including main effects and interactions of season, soil type and agronomic treatments were assessed using RxAPSIM. Year was the dominant component of variance at lower rainfall locations in WA and SA and all locations in NSW. Agronomy dominated at higher rainfall locations in WA and SA. Locations in VIC were between these two. The contribution of agronomy independent and dependent on rainfall (strategic and tactical agronomy respectively) has important implications for research, development, extension and management.