Mr Blair announced on Wednesday he would formally leave NSW Parliament on October 16. His Upper House replacement is Bathurst-based National Party member Sam Farraway.

Mr Blair said he had also been appointed Non-Executive Director and Chairman of Elf Farm Supplies, an environmentally sustainable mushroom compost business based in Western Sydney.

"Both of these roles provide me with the next great opportunity to pursue my passion for sustainable food and fibre production as well as developing new trade opportunities," he said.

"It is this research and these graduates who will be required to meet the challenges our primary industries face, not just now but into the future.

"Being on the ground and watching our communities struggle with one of the worst droughts on record was challenging, however it made me more determined to help find the ways in which we can strengthen our farming sector. We must learn to do more with less. Sustainable food production and waste reduction will play a critical role in achieving this.

"I have been humbled to serve alongside some of the state's best, not just in the Parliament, and in the public service, but on the farm as well. Rarely a day has passed in my time here when I haven't shook my head, surprised at how a 'curly haired boy from Goulburn' made his way to Macquarie Street and to the Cabinet room.

"I want to thank my dear family and friends, without whom none of this journey would have been possible. I want to thank my diligent staff who have pushed me to do better, kept me laughing and were unwavering in their loyalty.

"I want to thank the National Party and its members, as well as my colleagues on all sides of the House. Thanks for the debates, the jokes, the stunts, the confected outrage, the pats on the back, but mostly - thanks for the friendship. It is fair to say that I was always concerned less with the politics and more with the policy. However, I do hope that the changes I delivered across a range of portfolios go a long way in allowing the people of NSW to fully contribute to and share in the wealth of our state."

He said the NSW Ethics advisor has been consulted about these appointments in accordance with the Ministerial Code of Conduct and confirmed there is no conflict in me taking these roles."

CSU Deputy Vice-Chancellor Heather Cavanagh said Mr Blair's vast experience in agriculture would further strengthen the critical role played by the University in producing research and graduates that safeguard the industry's future.

"Over the course of more than two decades, spent in both the private and public sectors, Mr Blair has demonstrated a formidable understanding of the role played by primary industries, and the changes and challenges facing the industry," Professor Cavanagh said. "Charles Sturt University is delighted to welcome him aboard, and will ensure his wealth of experience and know-how is put to best use to serve the interests of farmers and other stakeholders."

Mr Blair was shaken earlier in the year after receiving death threats in the wake of the mass fish kills at Menindee Lakes. He said at the time this had affected his family greatly.