Soil Survey as a basis for Land Evaluation  http://www.eolss.net Deckers J, Spaargaren O & Dondeyne S. ©Copyright 2002 Eolss Publishers. All rights reserved. Encyclopedia of Life Support Systems 1 SOIL SURVEY AS A BASIS FOR LAND EVALUATION Deckers J. Institute for Land and Water Management, Catholic University Leuven (KUL), Belgium Spaargaren O. International Soil Reference and Information Centre (ISRIC), Wageningen, The Netherlands Dondeyne S. Institute for Land and Water Management, Catholic University Leuven (KUL), Belgium Keywords: soil classification, mapping and suitability, world (soil) reference base Content 1. Soil Surveying 2. Soil Mapping and Soil Classification 3. World Reference Base for Soil Resources (WRB), as a Basis to Streamline Soil Profile Information for Land Evaluation 4. Physical Land Evaluation based on Land Characteristics and Land Qualities 5. From Soil Survey to Soil Suitability and Land Evaluation. Case Study: Land Evaluation for Irrigated Rice in the West-African Sahel Related Chapters Glossary Bibliography Biographical Sketch Summary The objective of this paper is to elaborate on soil surveys in view of land evaluation, with emphasis on how soil surveys can meet the information demand for land evaluation. The paper starts by explaining what soil survey and land evaluation is about. Elements of soil survey and land evaluation relating to scale and purpose are discussed. The main focus will be on the linkage between soil survey, soil survey interpretation and physical land evaluation. Soil classification is a key component of soil surveys. The International Union of Soil Sciences (IUSS)-endorsed soil classification system "World Reference Base for Soil Resources" is briefly elaborated upon as a means to summarize the wealth of information from soil profiles for the purpose of land evaluation. The different steps from soil parameters, to land characteristics and land qualities for use in land evaluation are explained. The theory is illustrated by a worked example: land evaluation for irrigated rice in the West-African Sahel, wherein the Fertility Capability Classification (FCC) system is used to make the bridge between soil and land information.