Grain mineral contents in southeastern Australia

Grain nutrient concentrations for macronutrients and micronutrients were analysed from more than 70 NVT sites across southeastern Australia. All nutrients tested showed significant differences among regions. Values for the macro nutrient P were the most variable (3329±661 mg/kg) and was more than the commonly used value of 2900 mg/kg. The variation in grain P content could not be related to soil P test, fertilizer application or grain yield although values varied among regions and states. Sulphur and potassium levels also varied showed significant differences among regions, while grain zinc levels seemed lowest in regions characterized by alkaline soils.

These data suggest that regional or even paddock based nutrient concentrations may be required when construction nutrient balances. It may also be useful to use grain micronutrient content as a monitoring tool to indicate the need for fertilizer additions.
These results will be published at the Australian Society of Agronomy annual meeting in October 2012.