A former Norfolk landowners' leader, Piers Pratt, who was a custodian of the family estate for a quarter of a century, has died aged 57.

He was a former chairman of the Country Land and Business Association's tax committee, and was respected as a land agent across the eastern counties and further afield for his innovative thinking.

He relished the opportunity to care for the historic estate, which has been in the family since 1520. It also has its Kett's Oak, which dates from about 1260, where rebels gathered and camped before marching towards Norwich to join Kett's Rebellion in 1549.

While his late father cared for Ryston's St Michael's church, which is inside the 150-acre park, Piers was equally supportive of the county's churches. He became a chairman of the St Margaret's Trust, now King's Lynn Minster, and was chairman of the Norfolk Churches Trust in 2005. A keen cyclist, he even joined the annual fund-raising event.

As the elder son, he was given the Pratt family's traditional Christian names, Edward Roger and Piers. Born in September 1956, he was sent to Sunningdale and then Eton before going up to Selwyn College, Cambridge. He decided to become a chartered surveyor and joined a Lancashire firm of land agents, Ingham & Yorke. In the middle of the Forest of Bowland, he lived in a ramshackle wing of an old house, where the walls were so wet that wallpaper would not stick to the walls.

Having gained his FRICS qualification, he joined Strutt & Parker's Chelmsford office where he later became the firm's VAT expert and a partner. In 1990, when his father retired, he moved to the Norwich office. Then the estate had eight full-time and a dozen part-time staff, while his farming brother, Nicholas, has two working for him.

He moved the estate forward investing in irrigation and building a reservoir while looking after the estate's forestry, despite the financial challenges. Ryston's poplars, which had been a feature for more than a century, were at one stage home to about half of the country's 30 breeding pairs of golden orioles.

Trees – and notably oak – have always been a feature of the estate. An ancestor, the architect Sir Roger Pratt, who designed and rebuilt the house between 1667 and 1670, spent £26 9d 4d on trees. His great-grandfather started an arboretum in 1907. During his stewardship, Piers started growing willows again and did a millennium project to maintain the park's scattered planting. He was chairman of the Royal Forestry Society's East Anglia section for two years, chairman of the UK Poplar Forum, and the only rural business member of the East of England Regional Assembly.

He completed two costly repair projects – replacing the roof of the hall, which was so wet that water ran down the front stairs, and gave new life to the listed stable block. The hall's extensive walled kitchen garden was rejuvenated.

His health started to deteriorate after he had been elected in July 2005 to the two-year post as CLA Norfolk chairman.

He enjoyed shooting but was especially keen on walking, especially around the estate. He leaves a widow, Sarah, and three children, Louisa, George and Douglas.

A memorial service will be held at Ely Cathedral on Thursday, May 15 at 3pm.Michael Pollitt