Soil Survey, Classification and Mapping in Sri Lanka: Past, Present and Future

Abstract

Soil information is indispensable for sustainable use of the soil resource. Since its initiation in 1887, soil survey, classification and mapping activities in Sri Lanka have progressed through three successive stages. The latest soil maps of Sri Lanka developed through Sri Lanka-Canada soil resource project (1999–2004) are available at scales of 1:250,000–1:500,000. These choropleth soil maps delineate mapping units at soil series level, but due to the coarse nature of the mapping scale, majority of mapping units are either associations or complexes. These maps and the databases have primarily served for agricultural planning and management at its best. The state-of-the-art digital soil mapping techniques have been used in Sri Lanka mostly to generate soil information required for small-scale studies indicating a consistent development of expertise on advances in soil mapping. Presently, the need of soil information has expanded beyond its classical uses and has become a prerequisite for addressing environmental issues and food, energy and water security. These requirements are driving new demands for better soil maps at finer resolution. Catering the present soil information demand, the next national soil survey needs to be performed at a scale of 1:25,000 or larger using soil properties-based map legend. The multidisciplinary nature of the usage of soil information requires a collective decision of scientists on the soil properties to be considered for future mapping activities. Ultimately, the development of web-based national spatial soil information systems is a viable option to publish the next-generation digital soil information of Sri Lanka.