Duncan Joseph Greenwood. 16 October 1932—13 February 2010

Abstract

During his 55-year career as a highly distinguished scientist, Duncan Greenwood made a major contribution to the field of soil science and plant nutrition. His early studies on soil aeration revolutionized thinking on the mechanisms by which oxygen influences the activity of microorganisms and their metabolism of organic substances in structured soil. His ideas resulted in the ‘micro-site concept of soil aeration’, which is still widely accepted today. Later he turned his attention to the nutritional requirements of vegetable crops at a time when the horticultural industry was starting to introduce inorganic fertilizers. He developed a novel static model of N, P and K response, which he used to produce the first scientifically based inorganic fertilizer recommendations for 23 different vegetable crops. Not satisfied with this major development, Duncan started to create more sophisticated dynamic models using novel widely applicable relationships that took more account of the effects of weather on nutrient behaviour in the soil and plant. He not only used these to provide important insights into many of the complex interacting processes involved, but also incorporated them into some of the first computer-based decision support systems for practical site-specific fertilizer advice for the vegetable growing industry. The application of these advances had an important effect on the efficiency of crop production and the reduction of associated environmental impacts. Duncan continued to devise new models for nutrient and water use throughout the rest of his career and to explore ways of applying them in different areas of soil and crop science.