My colleague, mentor and friend Tom Addiscott, who has died aged 79, was an agricultural research scientist who helped to determine the benefits and the environmental consequences of using fertiliser on the soil.
Born in Brocket Hall, near Hatfield, Hertfordshire, which was then being used as a maternity hospital, to Dorothy (nee May), who died when Tom was eight, and Martin Addiscott, a second lieutenant in the second world war then manager of a fur factory, Tom was educated at Berkhamsted school before studying chemistry at Hertford College, Oxford, graduating in 1963.
He then spent a year as a United Nations volunteer working on improving soil quality in Tanzania. He helped to develop methodology to assess what quantity of nutrients, such as phosphorus, potassium and calcium, would be available to a farmer’s crops, and which nutrients were economically worth testing for and how to do it. In 1966, Tom started work at Rothamsted, the agricultural research organisation, completing an MA the following year and a PhD in 1973, both at Oxford University.
At Rothamsted, Tom developed some of the first computer models for the leaching of nitrate and later phosphate from soil, which can have damaging effects on the environment, including the creation of nitrous oxide, a greenhouse gas and green algal blooms in lakes. His work laid the foundations for much of the environmental computer modelling of the movement of water, nutrients and pollutants today.
Tom had a strong social conscience and retained a lifelong interest in Africa. As a member of the Farm Africa charity, he visited Kenya, Tanzania and Ethiopia. For many years he led the local branch of the IPMS trade union at Rothamsted, and was endlessly considerate and encouraging to his colleagues, with a mischievous sense of humour.
The Prince of Wales presented him with the gold medal of the Royal Agricultural Society of England in 1991. He was appointed a visiting professor at the University of East London in 1997 and awarded a DSc by Oxford University in 1999.
Tom retired from Rothamsted in 2002, but continued publishing articles on a range of issues related to soil quality in agriculture, on nitrate and human health, and complexity theory in a soils context. He was also licensed as a reader in the Church of England and was actively involved in the parish of Harpenden. He would happily discuss science, politics and religion over a pint. He also loved music, especially Bach and jazz.
In 1974 he developed a glioma, a type of brain tumour, requiring surgery and high-dose radiotherapy. Having almost died, he treated every moment from then on as a gift. The effects of the radiotherapy started 30 years later, leading to a slow deterioration in his mobility, speech and memory.
He is survived by his wife, Sally (nee Nicholas), whom he married in 1970, their daughter, Catherine, two granddaughters, Erin and Lucy, and his brother, Tony, and sister, Susanne.
