Dr Geoffrey Masefield, a specialist in tropical agriculture at Oxford University for nearly 30 years, has died aged 90.

An only child, Geoffrey Bussell Masefield was educated at the Dragon School, in Oxford, and at Balliol College.

In 1938, he published his first book of verse, I Am Not Armed, after seeking the advice of his cousin John Masefield, then Poet Laureate.

In 1947, he took up the newly created post of lecturer in colonial agriculture at Oxford University and was for many years a tutor at Balliol College.

He was among the first in the world to make a study of the prevention of famine and its relief.

He was well qualified for the role, having spent 12 years in the Colonial Agriculture Service in Uganda and travelled in 70 countries.

Towards the end of his career, Oxford University awarded him a doctorate of science.

He was also the second vicegerent of Wolfson College, and served for a considerable period as chairman of Oxford's Asia Committee.

His son Robin, 49, said his father died from "old age" in a nursing home and had not been suffering any illness.

He added: "My father loved Oxford. We lived at a house in The Moors, Kidlington, from the early 1950s until 1975, and enjoyed a country lifestyle where we grew all our own vegetables. My father also kept bees, hens and geese."

Robin shared his Kidlington childhood with brothers Thorold and Patrick, now 61 and 58 respectively, and sister Clare, 55.

Dr Masefield was also a special constable in Oxfordshire for 22 years and rose to the rank of special chief inspector.

He was associated with the Woodstock division and was on duty when Winston Churchill was buried at Bladon in 1965.

On his retirement, Dr Masefield and his wife Joy, now 88, moved to Wotton-under-Edge, Gloucestershire, where he became president of the Local History Society, supported the scout movement and the Gloucestershire Trust for Naure Preservation.

He continued to write poetry and a hymn he wrote, Jesus Friend To All Who Know, was chosen for his funeral at St Mary the Virgin, Wotton-under-Edge on August 10. He died on August 2.

Dr Masefield was personally unassuming and took great pride in the achievements of his wife and family.