Operations Research in Agriculture: Thornthwaite's Classic Revisited

In 1953 Operations Research (then called the Journal of the Operations Research Society of America ) published a paper that represented a model of practical operations research in the civilian field of agriculture. A recent reexamination, however, showed it to have gaps in exposition and discrepancies in reported times. Research to resolve these difficulties revealed that the original paper omitted some earlier steps in the work, and concentrated on the end-product of the research. This involved developing a climatic calendar based on rates of growth in pea plants, and applying it to scheduling sowing and harvesting vegetable crops for a firm producing frozen food. Behind this development, but unmentioned in the original paper, lay an analysis of water use by plants and the translation of growth measurements into temperature-related growth units applicable to many types of vegetable and fruit crops. This translation allowed plant maturing to be tracked easily and conveniently with a view toward harvest scheduling, and made the development of the climatic calendar possible. With it a farmer gains great economy in the costs and orderliness of planting and harvesting. This paper completes the picture of the work described in Thornthwaite's original paper. The management methods derived originally have remained in use unchanged for over forty years. Thornthwaite's approach and original attitude toward field research may still serve as guides for analysts working on practical problems today.