A third generation farmer, Don crops nearly 5000ha, with wife Maria and "right hand man" Andrew Lanigan, who works full time on the property, at Mittyack in the Victorian Mallee.

Previously applying the same blanket cover of fertiliser over his entire crop, Don began assessing the "lay" of his land with his agronomist Danny Conlan.

Using aerial photographs of his property and yield mapping from his harvester technology, Don has adjusted his fertiliser rates to suit soil type.

"There are three different zones over the paddocks," he said.

"A lower rate of fertiliser is spread on the caps of hills and the flats, where adequate of phosphorus has been applied to them over the past decade, while a higher rate of fertiliser is spread on the more productive land."

The property's internal fences have been pulled out for better weed control and efficiency gains with large machinery.