Fisons have available a wide range of basic quantitative data on the use of fertilizer on grassland, covering a period of 20 years. But such data is largely restricted to analyses by size of farm and region. To gain a deeper insight into the grassland market, a study of farmers behaviour and attitudes in relation to grassland management was undertaken. In particular, our objective was to seek to identify segments of the population having similar patterns of behaviour, in order to give guidance on the marketing and promotion of Fisons fertilizers to grassland farmers. Following extensive preliminary work, a questionnaire was devised and administered to a quota sample of 200 farmers. Certain problems of questionnaire design and analysis are discussed.