| Abstract: | It is surprising that despite all the pleas and policies regarding the development of sustainable land use systems, there is still considerable ignorance regarding the nature and significance of land resources. This paper traces the development and achievements of land evaluation during the 20th century, with particular reference to soils. The most active period was between 1950 and around 1980 with the development of soil and land capability surveys, methodological advances initiated with the FAO Framework for Land Evaluation, and regional land resource assessments. Thus there were considerable achievements in land evaluation by the early 1980s, and subsequently there have been important advances in the subject through the application of GIS, spatial analysis, modelling and fuzzy set algebra. Since the late 1990s there has been a phenomenal rise in interest in soil quality assessment. Considerable debate has focussed on definition, and methods of assessment and monitoring. The latter part of this paper discusses the major challenges to the development and application of land evaluation. The inadequacy of much soil survey data in terms of variables, quality, spatial coverage and scale is emphasised. Also, there is a continuing need to highlight the centrality of land resource issues in any attempt to develop sustainable land use systems. |
