Principles of a systems approach to agriculture: some definitions and concepts

A systems approach is needed to understand and manage a ‘farm’. This chapter examines the definition and concepts of farm systems, their structure, operation and management, the relationships among internal and external factors, response to changing circumstances, and modifications to deal with change. Study of a system requires definition of goals and objectives, boundaries and the structure and function of its components. Feedback mechanisms and interactions are important features of farm system structure and operation. Farm systems can often be better understood through analysis and the study of their sub-systems; and circle or problem-cause diagrams can assist this. Farmers design their systems to make best use of the prevailing climate and soil but a wide range of technological, commercial, social, political and personal factors determine farmers’ goals and management. Important characteristics of systems include: productivity, profitability, efficiency, stability, sustainability, equity, flexibility, adaptability and resilience. Efficiency of resource use should be optimised, bearing in mind Liebscher’s Law of the Optimum. Efficient use of energy and water are necessary for profitable production.Philip Tow, Ian Cooper, Ian Partridge, Colin Birch and Larry Harringto