ABSTRACT
Agronomy is the art and underlying science of handling the crops and soils to produce the highest possible quantity and quality of the desired crop products from each unit of land and soil, water and light (Ball, 1925), with a minimum use of resources in raising productivity associated with profitability, lower costs, and sustained competitiveness. Crop management and its scientific study — agronomy — encompasses the physical elements of the climate, soil and land, the biological constituents of the vegetation and soil, the economic
opportunities and constraints of markets, sales and profit, and the social circumstances and preferences of those who manage crop production. Such a management acts directly on a part of a plant, a whole plant, or a small group of plants in a stand, or else an amount of soil that can be worked by a person, animal, or machine. Each act of management influences the physiological processes of the plants, which, in turn, modify or regulate the flow of environmental resources — sunlight, water, and nutrients — to economic or useful products. However, management and its effects influence and are influenced by processes and events at much smaller and larger scales. Any human influence on a plant organ affects the
the climate, the topography of the land, and the economic and social factors such as markets and roads determine the type of management that is possible and feasible. Many individual acts of management together influence the pattern of land usage, the fertility of the land and its local microclimate, and the wealth and health of people and nations (Gregory, 1988; Loomis and Amthor, 1999; Azam-Ali and Squire, 2002).
