Call edition 2012

A new edition of the Prize of the Belgian Development Cooperation has been launched. This call is open until March 31st, 2011. You can read in the regulations whether you comply with the criteria for participation.

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Acid Neutralisation and Sulphur Retention in S-Impacted Andosols

Thomas DELFOSSE researcher laureate

°1978 Belgium
Agricultural Engineer, 2001

Acid Neutralisation and Sulphur Retention in S-Impacted Andosols

Volcanic activity is often a source of significant natural pollution, particularly with volcanoes that emit considerable quantities of sulphureous gas (mainly in the form of sulphur dioxide or SO2). Once emitted into the atmosphere, these sulphureous gases produce acid deposits into the environment around the volcano.
The research carried out by Thomas Delfosse assesses the impact of these acid emissions on the agronomic properties of the soil. The study site is the Masaya, an active volcano in Nicaragua, which constitutes an exceptional natural laboratory. The Masaya volcano is one of the largest volcanoes in the world that emit sulphureous gas (with emissions estimated at several thousands of tonnes of SO2 a day). This volcano also has the distinctive feature of being located in a caldera. The volcanic source is therefore located in a topographical floor in relation to the surrounding agricultural land that is directly affected by the volcanic plume. The acidic volcanic emissions have phenomenal consequences on local crops (mainly coffee). In fact the recent renewed activity of the Masaya has brought about the destruction of the primary forest and agricultural plantations over an area of about 22km².

Thomas Delfosse's study, which is one of the first research studies conducted on the subject, assesses the ability of the tropical soil to neutralize this important source of acidity and sets out the different physico-chemical mechanisms linked to the future of the sulphureous species once they have been incorporated into the soil.
The study provides fundamental data that is very useful to the sustainable development of agricultural land in developing countries as well as practical low-cost solutions to reduce the impact of these acidic emissions, solutions that will be able to be applied to other volcanic regions where similar acidification phenomena have also been observed (Rincón de la Vieja in Costa Rica and Ambrym in Vanuatu).

report: Prof. A. Bernard, Laboratory of Geochemistry and Applied Mineralogy, Université Libre de Bruxelles, Belgium