Accessing and assessing legacy soil information, an example from two provinces of Zambia

Abstract

Soil information is essential for agricultural research and development. In developing countries like Zambia, the availability of soil information is limited by the cost of new soil surveys. Legacy soil information could be useful to fill this gap. This study evaluated the availability of legacy soil information in Southern and Eastern Provinces of Zambia. We also examined the survey scales, legends, boundary density and map texture. We examined a number of exemplar transects undertaken by C.G. Trapnell from 1932 to 1942 in the region, evaluating the information provided on soil, vegetation, landscape and farming systems. An overview of this legacy was presented to a workshop of varied stakeholders in Lusaka, and their opinions on its utility were elicited. More than 60% of large-scale surveys known to have been conducted in the two provinces could not be traced and among those traced some map-sheets were not available. Most of the survey reports exist as hard copies and some are in poor condition, while only 7 are available online on the ISRIC website as scanned copies. The map scale and texture were not entirely consistent with general expectations, with map texture consistent with a smaller publication scale in assessed map-sheets. Stakeholders regarded the legacy information as a valuable resource, despite some limitations, suggesting that some of its features could usefully be reproduced in modern soil information. The holistic assessment provided for soil map units may be more accessible than single-property maps. Accessibility and understanding of soil information is seen as a limitation. There is an urgent need to preserve the legacy soil survey reports and maps that are still available in Zambia, and in other countries. This entails physical preservation of material, making it available, and studying it closely with current and retired soil surveyors to preserve their recollection of how it was produced and their understanding of how it should be interpreted. The preservation should include scanning of hardcopy reports and storage in national, regional, and global soil survey data hubs with links provided for easy access. Stakeholder enthusiasm for the format of legacy soil surveys suggests that renewed systematic soils surveys would be valuable.