He was conscripted into the British Army in May 1918 and attached to the Queen's Own Cameron Highlanders, being discharged on the conclusion of World War I.

After a brief period in South Africa,[2] Roberton immigrated to Australia in 1922, settling in the Riverina, and began working as a sharefarmer growing wheat for the Scottish Australian Investment Company Limited.

[1] In 1930, Roberton began writing a weekly column for the Coolamon-Ganmain Farmers' Review under the pen name "Peter Snodgrass".

In 1939 he proposed the so-called "Roberton Scheme" for the permanent stabilisation of wheat prices via a quota, a version of which was adopted by the federal government in 1942.

His book Now Blame the Farmer was published by Angus & Robertson in 1945 and included various proposals for government land and agricultural policy.

[1] At the 1940 federal election, Roberton was one of two candidates endorsed by the Country Party in the seat of Riverina, along with the incumbent MP Horace Nock.

The Sydney Morning Herald reported in January 1965 that his time in the ministry had been "marked by conscientious effort rather than spectacular achievement".