Concepts in production ecology for analysis and quantification of agricultural input-output combinations.

Definitions and concepts of production ecology are presented as a basis for development of alternative production technologies characterized by their input-output combinations. With these concepts the relative importance of several growth factors and inputs is investigated to explain actual yield levels and resource-use efficiencies. Differences between potential and actual levels are analyzed to open ways for improved production technologies. The basis of the analysis is knowledge of basic physical, chemical, physiological and ecological processes at soil, field and crop level. New production technologies and their input-output combinations can be used in studies aimed at the exploration of options for sustainable agricultural production systems and land use. The concepts allow a systematic analysis and quantification of input-output combinations and clearly discriminate between bio-physical possibilities and socio-economic constraints and objectives. They help in defining objectives and means for agricultural production and land use, and may be valuable as aids to communication between various disciplines involved in studying the possibility and feasibility of future production technologies and land use options. The concepts production level, physical environment, target-oriented approach, production technique, production activity, and production orientation are applied to identify new technologies and production systems at various levels of scale, each requiring different types of information. In this paper some examples of applications are given at field, farm and at regional level.