His countless hours of work meant he was often going to meetings.
Mr Sadler said the role on the trust had been a good way to satisfy his interest in education.
"Lands Trust was an outlet that I could use to express my professional skills and contribute something back to the community."
As chairman of the trust, he led the establishment of education initiatives and established grants to Wairarapa schools and early childhood centres.
The trust encourages and supports UCOL, trades training and apprenticeships, and young people in education.
Mr Sadler is also credited for significantly increasing the value of the trust's property portfolio and assets, and helping get Aratoi off the ground.
During Mr Sadler's first four years as chairman, grants to the community increased by 50 per cent to reach the million-dollar mark.