ISSUES OF SUSTAINABILITY AND SUSTAINABLE LAND MANAGEMENT

The concept of sustainability shows many facets. Ecologists, environme ntalists, agronomists, sociologists, economists and politicians use it with different connotations. In addition, the sustainability of land management systems varies in space, according to climate, soil, techno logy and societal conditions. Sustainable farming systems vary also in time, as they evolve and may collapse, frequently together with the c orresponding sociosystems. Because of its complexity, sustainability i s difficult to measure directly and requires the use of appropriate in dicators for assessment. A good indicator is free of bias, sensitive t o temporal changes and spatial variability, predictive and referenced to threshold values. Relevant data are often incomplete or inadequate for indicator implementation. To embrace the whole width of sustainabi lity, several methods and techniques should be used concurrently, incl uding land evaluation and coevolutionary, retrospective and knowledge- based approaches. It is, however, at the application level that major constraints arise. A sustainable land management system must satisfy a large variety of requirements, including technological feasibility, e conomic viability, political desirability, administrative manageabilit y, social acceptability, and environmental soundness. Real world condi tions at farm and policy-making levels need to be substantially improv ed to achieve sustainable land management.